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3. Design, Functions

3.1 GeneralChapter 3.1, � 43 is subdivided into the following sections

� System overview (Chapter 3.1.1, � 43) and

� Fundamentals of the evaporation technology (Chapter 3.1.2, � 46).

3.1.1 System overview

Fig. 3-1 General arrangement diagram of the BAK 1131

A Process chamber with process unitB System controlC Handling systemD Pumping systemE Power distributorF RF-Generator (upper level)G Cryo compressor (upper level)H Roughing pump (upper level)

A

D D

C

Gray Room Area

Upper Level

Cleanroom Area

B

B

E

F

G

G

H

H

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The BAK 1131 is used for depositing thin metallic films under vacuum by evaporation. A complete evaporation coating process comprises the following steps:

1 Mounting the substrates on a substrate holder system.The substrate holder system comprises:

� Substrate holder - spherical steel calotte with round recesses into which the individual substrates are placed.

� BD 500 rotary drive which continuously rotates the calotte to ensure a uniform heating and coating process across all substrates.

2 Insertion of the substrate holders into the process chamber by means of a semi-automatic handling system.The handling system comprises:

� Loading arm for semiautomatic loading and unloading of the process chamber with substrate holders (calotte).

� Two Manually operated swivel arms for populating the substrate holders and for transferring the populated substrate holders to the loading arm.

3 Evaporation coating of the substrates in the process chamber with various mate-rials.The process unit comprises:

� Evaporation system - Depending on the material to be evaporated inductive sources type IHS 100 (for Au, Ti and Cu), IHS 120 (for Pb and Sn) or a chim-ney source (for Cr) are used.

� Film thickness measurement unit Sentinel III (Leybold) for inspecting the film by means of Electron Impact Emission Spectroscopy (EIES).

� Calotte heater for heating the substrate to the required process temperature. An electrical back side heater, subdivided into several heating zones, is used.

The pressures required for the evaporation coating process are produced by a vacuum pumping system. This pumping system is located on the back of the process chamber and is equipped with the following vacuum pumps:

� Fore vacuum pumps (Leybold) - dry-compression vacuum pump Dryvac 100 P (2 units) and Roots pump WAU 1001.

� High vacuum pumps (Leybold) - cryopump Coolvac 10010 (2 units).

For supplying the BAK 1131 with electrical power, cooling water and compressed air the following components are required:

� Media cabinet for cooling water and compressed air.

� Power distributor.

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Fig. 3-2 Block diagram of the BAK 1131

Detailed information on the individual components of the BAK 1131 can be found in the following chapters:

� Chapter 3.2, � 47 - Process chamber

� Chapter 3.3, � 49 - KHAN NT system control including all control racks

� Chapter 3.4, � 53 - Process unit with evaporation system, substrate holder system, substrate heater and film thickness measurement

� Chapter 3.5, � 66 - Substrate holder system

� Chapter 3.6, � 69 - Handling system

� Chapter 3.7, � 72 - Pumping system

� Chapter 3.8, � 74 - Electrical system with power distributor, signal distributor and dis-tribution boxes

� Chapter 3.9, � 79 - Media supply with water and compressed-air circuits.

Process chamber

Pumping system

Handlingsystem

Mediasupply

System controlKhan

With evaporation system,substrate holder system,substrate heater,film thickness measurement

Process unit

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3.1.2 Fundamentals of the Evaporation Technology

Evaporation is the oldest technology for producing thin films under vacuum conditions. In many applications it has been replaced over the years by other technologies such as sputtering or PECVD. However, whenever large surfaces are to be coated with high film growth rates the evaporation technology is still a commonly used and economical solu-tion.

The principle of the evaporation technology is very simple. The material to be evapo-rated is heated in a process chamber under vacuum conditions to a temperature where it evaporates. The material can be heated with an electron beam, through inductive exci-tation, or through electrical resistance heating. On all parts in the process chamber that are not protected by shutters a thin film of the evaporated material is deposited. All parts arranged on the same spherical surface around the material to be evaporated receive a film of identical thickness.

Fig. 3-3 Principle of the evaporating technology

A SubstrateB Coating layerC Evaporated materialD CrucibleE Coating materialF Heat

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3.2 Process chamberThe process chamber is fabricated from stainless steel. The inside surfaces are finely polished. The process chamber features a number of flanges for mounting the source flange, the rotary drive, the film thickness measurement unit and the pumping system. The tubular coils welded to the outer surface of the process chamber and the process chamber door are used for heating and cooling the process chamber.

The process chamber is mounted on a welded steel frame.

Fig. 3-4 Process chamber with door and mounting frame

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Through the two sight glasses in the front of the process chamber the interior of the pro-cess chamber can be observed during the coating process.

Fig. 3-5 Sight glass and viewport of the process chamber/door

The process chamber normally opens toward the left. When the door is open, a large cross-section of the process chamber is free which means that easy accessibility to the built-in equipment is ensured.

The locking facility (Fig. 3-5, � 48) of the process chamber door consists of a pneumatic cylinder with a horizontal piston guide. The pneumatic cylinder is pivot mounted and can perform an angular movement. The horizontal guide is designed in such a way that when the pneumatic cylinder is retracted the distance between the piston rod and the process chamber door is so short that the door is locked by the piston head. In the extended condition the distance between the piston and the process chamber door is large enough so that it can be unlocked and opened.

Fig. 3-6 View from the right-hand side to the process chamber - Process chamber locking device shown in red:

A Pneumatic cylinderB Swivel jointE Guide of the pneumatic cylinderD Process chamber

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3.3 System controlThe BAK 1131 is monitored and controlled by the KHAN-PC. It comprises the following functions:

� Control and monitoring of the pumping system

� Control and monitoring of the coating process

� Process visualization

Fig. 3-7 Block diagram of the KHAN NT system control

Ethernet

Mouse

Printer

Host

Keyboard

I/O Modules

Control Rack

Power Rack

Plant

M34, M45M62, M66

TFTDisplay

Keyboard

M45

Sentinel 1/2 CTI 1/2 QMS

Cleanroom

SwitchBox

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The KHAN NT PC as well as the controllers for the vacuum pumps and film thickness measurement interfaced to the KHAN NT are installed in two control racks in the grey room area of the BAK 1131 on the left-hand side of the process chamber.

The KHAN NT system control is operated via two computer keyboards (with additional mouse control) of which one is located in the cleanroom and one in the greyroom. Con-trol rack 2 contains a switching box through which the authorized personnel can activate one of the two computer keyboards. For the system control visualization a computer ter-minal is used which can optionally be observed from the cleanroom or the greyroom side.

The 19" rack module of the KHAN NT system control contains the following compo-nents:

� PC, CPCI Pentium 200 MHz

� M66 digital input/output module

� M34 analog input module

� M62 analog output module

� PCI bus

� Basic KHAN NT with 3.5" floppy drive, CD-ROM drive, CPCI 3HE 19", 5 slots

The signal distribution unit for signal adaptation between the control section and the power rack of the BAK 1131 is located on the back of the control rack.

The film thickness measurement system (SENTINEL) and the external handling system are equipped with their own monitoring units which communicate with the KAHN system control via serial interfaces.

The two control racks of the BAK 1131 (Fig. 3-8, � 51) contain the following components that are monitored and controlled by the KHAN NT system:

� Sentinel 1 and 2, User's guide "Sentinel III control unit"Controller(s) for film thickness measurement. Depending on the process the BAK 1131 is equipped with one Sentinel controller (PbSn) or two (TiCrCuAu).

� CTI «CM 400» On-Board Control Unit and Monitor. This is the supply and control unit for the CTI cryopump. For additional information on these units please refer to the separate CTI operating instructions.

� RF-Generator Control Unit, User's guide "Hüttinger RF Generator"Control unit(s) for RF generator(s) on upper level.

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Fig. 3-8 Control rack CrCuAu of the BAK 1131

SENTINEL 2

SENTINEL 1

KHAN NT

FLAT PANEL

TFT 15.1 ´´

KEYBOARD

UPS

SOCKET

115 VAC

KEYBOARD SWITCH

TIG/2 10/300

TIG/3 10/300

EMO

SWITCH

CM 400/1

LAPTOP

CM 400/2

COLOR INKJET PRINTER

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Fig. 3-9 Control rack PbSn of the BAK 1131

The following components linked to the KHAN NT system control are also installed in the control racks:

� Keyboard Switch-Unit

� Switch box for the KHAN NT input keyboards located in the greyroom and clean-room. This switch box is installed in a lockable pull-out tray.

� Interface box for outputting process parameters to an X-T recorder.

UPS

KHAN NT

FLAT PANEL

TFT 15.1 ´´

KEYBOARD

SOCKET

115 VAC

KEYBOARD SWITCH-UNITPULL-OUT TRAY

TIG/1 20/300

EMO

SWITCH

CM 400

DRAWER LAPTOP

CM 400

COLOR INKJET PRINTER

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3.4 Process UnitThe process unit of the BAK 1131 comprises the following components:

� Evaporation system (Chapter 3.4.1, � 53).

� Film thickness measurement system (Chapter 3.4.2, � 60).

� Calotte heater (Chapter 3.4.3, � 64).

Fig. 3-10 Block diagram of the BAK 1131 process unit

3.4.1 Evaporation system

This Chapter is subdivided into the following sections:

� Overview (Chapter 3.4.1.1, � 54) with a description of the source flange and its com-ponents.

� Inductive source (Chapter 3.4.1.2, � 56) with a detailed description of the design and function of the installed inductive sources. These sources are used for evaporating gold, copper, titanium, lead and tin.

� Chimney source (Chapter 3.4.1.3, � 59) with a detailed description of the design and function of the installed chimney source for chromium evaporation.

Process chamber

Calotte header

Calotte withsubstrates

Sensor

Filmthicknessmeasurement

Evaporationsystem

Voltage supplyand control

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3.4.1.1 Overview

The evaporation system of the BAK 1131 is mounted as a compact unit on the source flange located on the underside of the process chamber. This source flange is equipped with different components, depending on the evaporation process (PbSn or TiCrCuAu).

The following components are located on the source flange for the TiCrCuAu process:

� IHS 100 inductive source for gold (Au) evaporation with shutter, power and cooling water connections.

� IHS 100 inductive source for copper (Cu) evaporation with shutter, power and cooling water connections.

� IHS 100 inductive source for titanium (Ti) evaporation with shutter, power and cooling water connections.

� Chimney source for chromium (Cr) evaporation with shutter, power and cooling water connections.

Fig. 3-11 Source flange of the BAK 1131 process unit for the TiCrCuAu process (standard configuration)

A IHS 100 inductive source for TiB IHS 100 inductive source for AuC IHS 100 inductive source for CuD Chimney source for CrE Shutters

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The following components are located on the source flange for the PbSn process:

� IHS 120 inductive source for lead (Pb) and tin (Sn) evaporation with shutter, power and cooling water connections.

� Indexer for automatic crucible change of the inductive source.

Fig. 3-12 Source flange of the BAK 1131 process unit for the PbSn process: 9-hole configuration (possible also 5-hole configuration)

A Indexer (with IHS 120 source beneath)B Shutter (watercooled)C Crucible

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3.4.1.2 Inductive Source

Function The peculiarity of the inductive source is that the energy required for the evaporation process is transferred to the material to be evaporated without contact by means of an electromagnetic alternating field. There is no contact between the electromagnetic field generator and the evaporation material, and there is no heat transmission by radiation.

The transmission principle is similar to a transformer. The source of the electromagnetic field corresponds to the primary winding of the transformer (item C in Fig. 3-13, � 57). The material to be evaporated in which an electrical current is induced, corresponds to the secondary winding of the transformer (item E in Fig. 3-13, � 57).

This transmission method can only be used for materials with free charge carriers (met-als) for dipole moments (dielectrics) that can be excited by electromagnetic fields. The heat development in the materials is based on the physical principle that the electrical currents induced in the materials dissipate a large amount of their energy in the form of heat. With the electromagnetic field frequencies typically used in Unaxis systems the required heat is largely created through eddy current dissipation.

In Unaxis inductive sources the material to be evaporated is located in a crucible. The electrical energy and consequently the heat is induced in the crucible rather than directly in the evaporation materials. The constant induction of the crucible through power cou-pling offers several advantages:

� High stability of the evaporation process.

� Constant evaporation rate independent of the amount of material in the crucible.

� No spitting effects resulting from the skin effect with direct inductive heating of the evaporation material.

Design The IHS 100/120 inductive sources comprise the following elements:

� Source holder

� Water-cooled HF vacuum feedthrough

� Source body with water-cooled high frequency coil, insulated crucible holder, and water-cooled source hood

� Dielectric or metallic crucible for evaporation material. Depending on the material, crucibles with different geometries are used in order to achieve optimum evaporation processes

� Electro-pneumatic shutter for covering the source opening.

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Fig. 3-13 Design of the IHS 100/120 inductive source based on an IHS 100:

A Source holderB HF vacuum feedthroughC High frequency coilD Crucible holderE CrucibleF Source flange

To achieve better inductive coupling between the coil and the crucible, coils with a square cross-section are often used because they have a large coupling surface. Opti-mum coupling of the high frequency (150 kHz) into the primary coil is achieved by means of an RF Exciter located directly below the vacuum feedthrough.

Depending on the crucible the IHS 100 source is designed for evaporating the following materials:

� Titanium (Ti)

� Copper (Cu)

� Gold (Au)

� Aluminum (Al)

� Silicon (Si)

The crucibles are either made of Tungsten (Ti, Al, Cu), Molybdenum (Cu) or Graphite (Si). In case of Gold or Aluminum the Tungsten crucibles are located in a graphite holder acting as a susceptor.

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Fig. 3-14 Crucible and crucible holder of the IHS 100 inductive source (example for Al):

A Crucible.B Crucible holder.C Mounting rod.D Fixing screws

For evaporating large amounts of material with a low melting point (such as Pb and Sn), the IHS 120 inductive source is used. This source has crucibles with a capacity of 300 cm3. For the IHS 120 source an optional indexer is available through which up to 9 cru-cibles can consecutively be inserted into the IHS 120 inductive source without opening the system.

Fig. 3-15 Indexer for semi-automatic crucible change on the IHS 120 (example: 9-hole configuration)

A Recess for crucible (9 pieces)

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3.4.1.3 Chimney Source

Chimney sources are based on the principle of resistance heating: The current flowing through an electrical resistor is dissipated as heat (= current x voltage drop across the resistor).

Fig. 3-16 Chimney source

A Tantalum chimneyB Water-cooled chimney jacketC Mandrel for mounting the Cr slackD Source holder

The chimney source for chromium evaporation comprises the following elements:

� Source holder with tantalum chimney and water-cooled jacket.

� Water-cooled power feed-through.

� Electro-pneumatic shutter cover covering the shutter opening.

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3.4.2 Film thickness measurement

The thickness of the film to be deposited by the coating is controlled and monitored by a Sentinel III film thickness measurement system (Leybold Infinicon).

The film thickness measurement is based on the effect of Electron Impact Emission Spectroscopy.

The EIES sensor is located between the evaporation source and the substrate calotte. Through a rectangular opening which is directed toward the evaporation sources evap-orated material flows into the EIES sensor. On the path through the space between an electron source (filament with shutter) and a lamellar Faraday collector the coating material is excited by electron impact. The wave length of the emitted light is specific to the material and the intensity is proportional to the incoming material flow. It is measured during the entire coating process. The cumulative radiation is translated into the momentary substrate film thickness by means of corresponding calibration facts.

The basic version of the Sentinel III film thickness measurement system comprises the following components:

� Sensor unit.

� Sentinel III sensor control unit (SCU).

� Sentinel III deposition controller.

Fig. 3-17 Block diagram of the Sentinel III film thickness measurement system

Process chamber

Calotte withsubstrates

Sensor

Evaporationsystem

PMT

Sensorcontrol unit

Depositioncontroller

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3.4.2.1 Sensor unit

The sensor unit of the Sentinel III film thickness measurement system is located on the left-hand side or inside the process chamber.

For measuring the film thickness of an evaporation material the sensor unit comprises the following components:

� Electron impact emission spectroscopy (EIES) sensor.The sensor comprises:

� Emitter unit consisting of a filament wire with shutter and electrical connection.� Lamellar Faraday collector.� Cover with sensor window.� Mounting flange.

� Hollow tube with mounting flanges, evaporation coating protection, vacuum window and high vacuum tight connector

� Photomultiplier tube (PMT) with a material-specific, optical band filter.

If one sensor unit is used for monitoring the evaporation of two different materials, the sensor unit comprises the following additional components:

� Semitransparent mirror (50% transmission and 50% reflection).

� Photomultiplier tube (PMT) with material-specific optical band filter for material 2.

For film thickness measurement of four materials (TiCrCuAu) two of the above sensor units are used. Both sensor units are mounted in parallel on a common flange.

For additional information on the sensor unit please refer to the user's guide "Sentinel III Control Unit", user's guide "Sentinel III, Deposition Controller, Manual".

Fig. 3-18 Sensor unit (TiCrCuAu)

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Fig. 3-19 Sensor unit for measurement of the film thickness of two different materials

3.4.2.2 Sentinel III SCU sensor control unit

The Sentinel III SCU sensor control unit supplies the power to the filament, to the pho-tomultiplier cascades, and the photomultiplier output signal gain.

For the four-layer evaporation coating process (TiCrCuAu) two sensor control units are used. The sensor control unit is attached to the corresponding mounting flange of the sensor tube by means of a metal bracket.

For additional information on the Sentinel III SCU sensor control unit please refer to the user's guide "Sentinel III Control Unit", user's guide "Sentinel III, Deposition Controller, Manual".

Fig. 3-20 SCU sensor control and photo mulitplier tube

PMT 2

Filter 2

PMT 1

Filter 1 Mirror Window

Vacuum

Sensor

h 1

h 2

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3.4.2.3 Sentinel III deposition controller

The sentinel III deposition controller monitors and controls the Sentinel III sensor control unit.

The deposition controller is located in the left-hand control rack in the greyroom area of the BAK 1131 on the left-hand side of the process chamber:

� Controller 1 for PbSn or TiCr coating (upper module).

� Controller 2 for CuAu coating (lower module; only configured for four-layer coating process).

The controller is equipped with a keyboard, a monitor, and terminals for connecting a Sentinel III SCU sensor control unit and the BPU 431 system control.

Fig. 3-21 Deposition controller of the Sentinel III film thickness measurement system

For additional information on the Sentinel III deposition controller please refer to the user's guide "Sentinel III Control Unit", user's guide "Sentinel III, Deposition Controller, Manual".

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3.4.3 Substrate heater (TiCrCuAu only)

For heating the back of the substrates a metal hood is installed above the substrate holder. This heater functions according to the principle of resistance heating.

Fig. 3-22 Block diagram substrate heater

A Process chamber.B Substrate heater hood.C Temperature sensor.D Substrate heater.E Power supply of the substrate heater.

To improve the temperature distribution the heater is subdivided into three 120° heating zones. Each heating zone consists of an "inner", a "central" and an "outer" heating zone with a heating power of 2 kW each. The total heating power is 18 kW.

All three "inner", all three "central" and all three "outer" heating zones are connected in parallel to a common control circuit. The three vacuum feedthroughs for the "inner", "central" and "outer" heating currents are located on the top of the process chamber.

E

C

D

BA

KHAN

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Fig. 3-23 Substrate heater - arrangement of the heating zones:

A Heating zone 1B Heating zone 2C Heating zone 3D "Inner" heating zoneE "Central" heating zoneF "Outer" heating zoneH Power feedthrough (3 units)

The temperature is measured by a thermocouple in the metal hood above the heater and the set point is specified by the temperature controller via the KHAN NT system con-trol. The heating currents are monitored.

The vacuum feedthrough for the thermocouple of the substrate heater is located on the top of the process chamber.

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3.5 Substrate holder systemThe substrate holder system comprises:

� Rotary drive (Chapter 3.5.1, � 66)

� Substrate holder (Chapter 3.5.2, � 68)

� Control

Fig. 3-24 General arrangement diagram of the substrate holder system:

A Rotary driveB Substrate holderC KHAN NT system controlD Process chamber

3.5.1 Rotary drive

The rotary drive consists of a DC motor, a gear unit, and a high-vacuum-tight rotary feedthrough type BD 500 (see Fig. 3-25, � 67). The rotary drive for the substrate holder is mounted as a compact unit to a flange (DN 250 ISO) on the ceiling of the process chamber. Its speed can be steplessly controlled.

A DC shunt motor with tacho generator for monitoring the rotational speed is used. The speed is governed by a control board which is installed in the power chassis of the sys-tem. The rotary drive is controlled and monitored by the KAHN system control.

For additional information on the rotary drive control please refer to the user's guide of the KHAN NT system control, and Chapter 4., � 85 of this manual.

KHAN

CA

B D

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Fig. 3-25 BD 500 rotary drive:

A DC motorB Gear unitC Rotary drive housing (stationary)D Substrate holder mount (rotating)

For transferring a substrate holder to the rotary drive the substrate holder mount (item C in Fig. 3-25, � 67) must be in one of two defined angular positions.

� Rotary drive locked

� Rotary drive unlocked

These positions are monitored by two inductive sensors in the cover of the rotary drive which are offset at an angle of 60°. These two sensors respond to a brass blade located on the drive gear of the rotary drive.

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3.5.2 Substrate holder

The substrate holder consists of a spherical steel element (calotte) with recesses for inserting the individual substrates.

Fig. 3-26 Substrate holder (calotte)

A Recess for substrateB Holder mount

The substrate holder is transported into the process chamber by means of a semi-auto-matic loading arm.

For additional information on the loading procedure please refer to Section 3.6 of this user's guide.

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3.6 Handling System

3.6.1 General

The BAK 1131 is equipped with a handling system (lazy susan) which comprises:

� Loading arm for loading/unloading the chamber with substrate holders (calotte).

� Two dome lifts for loading/unloading the substrate holder with substrates.

With the exception of the electrically performed horizontal loading arm movement and the pneumatic locking of the substrate holder, the handling system is operated manu-ally.

For transferring the substrate holder from the dome lift arm to the loading arm and for loading the process chamber, the loading arm features a programmed logic controller (PLC) and a control panel through which all transfer positions of the loading arm can be approached semi-automatically. The correct loading arm position is measured with the zero sensor via a displacement measurement system and transmitted to the PLC of the handling system. While a normal handling sequence is being executed on the control box the PLC automatically stops the loading arm at each transfer position.

Fig. 3-27 Handling system of the BAK 1131

A Loading armB Substrate holder mount of the loading armC Control panel for loading armD Dome lift with two armsE Substrate holder mount of the dome lift arm (two units)

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Fig. 3-28 Operator control box of the BAK 1131 handling system

A Emergency stop buttonB Touch screenC Handle

On the top behind the loading arm control panel there is a handling stop key which shuts off the handling system only.

3.6.2 Transfer of a Substrate Holder

From the swivel arm to the loading arm

� The sensor on the swivel arm signals: Swivel arm with substrate holder in transfer position.

� Loading arm is manually moved to the transfer position.

� PLC signals: Loading arm and swivel arm in transfer position, swivel arm populated with substrate holders -> swivel arm automatically activates the interlocking and the loading arm blow automatically accepts the substrate holder.

From the loading arm to the swivel arm

� The sensor on the swivel arm signals: Swivel arm in transfer position.

� Loading arm with substrate holders is manually moved to the transfer position.

� PLC signals: Loading arm and swivel arm in transfer position, loading arm populated with substrate holders -> swivel arm automatically locks the substrate holder, and the empty loading arm below can be moved downward.

SERV

AL

ATTENTION

CRASH-DANGER

ORIGIN ORIGIN(NOT) OK (NOT) OK

OPER

CLOR

A B

C

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From the loading arm to the rotary drive

Fig. 3-29 Substrate holder mount on the loading arm

A Substrate holder mount (rotatable)B Adjusting screws for the angular position of the loading armC Optical sensor (substrate holder on sensor yes/no)D Inductive sensor (substrate holder in position)E Spring pin for positioning the substrate holder

� Before the substrate holders is transferred from the loading arm to the rotary drive the following conditions must be met:

� Optical sensor (item C in Fig. 3-29, � 71) signals that a substrate holder is po-sitioned on the loading arm.

� Inductive sensor (item D in Fig. 3-29, � 71) signals that the angular position of the substrate holder is correct for the transfer.

� Sensor on the rotary drive signals the correct transfer position of the rotary drive (see Chapter 3.5.1, � 66).

� Loading arm with substrate holder is moved semi-automatically into the transfer po-sition.

� Rotary drive locks the substrate holder by performing a 60° rotary movement.

� Loading arm can now be removed downward.

The transfer of a substrate holder from the rotary drive to the loading arm is performed analogously.

A

B

CD

E

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3.7 Pumping systemThe pumping system of the BAK 1131 is located in the greyroom immediately behind the process chamber. The pumping station comprises the following main components:

� Fore vacuum pumping station (items 4, 5, 6, 7, 11, 12 and 15 in Fig. 3-30, � 72).

� High vacuum pumping station (items 2, 3, 13 and 14 in Fig. 3-30, � 72).

� Venting unit (items 8, 9 and 10 in Fig. 3-30, � 72).

Fig. 3-30 Pumping system diagram of the BAK 1131

1 BAK 1131 process chamber2 Gate valve DN 500 ISO3 10010 Coolvac cryopump4 Dryvac 100 P dry-compression vacuum valve5 WAU 1001 Roots pump6 Bypass valve EVL 160 P7 DN 40 KF fore vacuum valve, angle valve8 EVL 025 P vent valve9 EVL 016 P vent valve10 EVN 116 gas regulating/shutoff valve11 High vacuum gauge12 Pirani vacuum gauge13 Pirani vacuum gauge14 High vacuum gauge15 EVL 063 P angle valve

( )

1

2

3

14

7

12

32 7

12

5

6

13

4

1198

10

Nitrogen

Exhaust

4

12

11

13, 14

11

15

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Fore vacuum pumping station

The fore vacuum pumping station consists of two sections:

� Pumping station for bypass pumping the process chamber.The coarse vacuum is generated by two dry-compression vacuum pumps Dryvac 100 P, interconnected by an angle valve and a Roots pump type WAU 1001. The an-gle valve between the two dry-compression vacuum pumps is closed during the re-generation of the cryopumps (for details see Fig. 3-30, � 72). The bypass line can be shut off by an electro-pneumatic bypass angle valve. For measuring the vacuum in the process chamber a Pirani gauge head is flanged into the vacuum line between the Roots pump and the bypass angle valve.

� Pumping station for generating the fore vacuum for the high vacuum pumps.

For generating the fore vacuum for the high vacuum pumps a dry-compression vacuum pump Dryvac 100 P is used. The vacuum line between the fore vacuum pump and the two high vacuum pumps can be shut off by two electro-pneumatic angle valves (DN 40 KF).

High vacuum pumping station

The high vacuum pumping station comprises the following components:

� T-piece DN 500 flanged directly to the back of the process chamber.

� 2 gate valves which are installed on the free flanges of the T-piece DN 500.

� 2 Coolvac 10010 cryopumps for generating the high vacuum in the process chamber. The cryopumps are flanged directly to the two gate valves.

� One combination vacuum gauge head for measuring the vacuum in the process chamber, and one high vacuum gauge head for leak test measurements.

Venting device The 2-stage venting devices is designed as follows:

� For venting the process chamber under high vacuum conditions the gas is admitted slowly via the EVN 116 gas regulating valve and the upstream electro-pneumatic an-gle valve type EVL 016 P.

� When the minimum pressure has been attained by venting via the EVN 116 gas reg-ulating valve, the electro-pneumatic EVL 025 P vent valve opens and the process chamber is quickly vented to atmospheric pressure via two parallel gas lines.

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3.8 Electrical system

3.8.1 Overview

The circuit diagram of the BAK 1131 can be subdivided into three sub-busses:

� Bus 1 - Rotary drive, auxiliary voltages and bus 3 (vacuum pumps).

� Bus 2 - Voltage supply of the sources and the substrate heater (TiCrCuAu process only).

The designations used in the following block diagram are identical with those in the cir-cuit diagrams of the electrical documentation.

Fig. 3-31 Electrical block diagram of the BAK 1131 (Pb/Sn without red marked components)

M

RotaryDrive

Sentinel

Sentinel

Busbar 1

1x230V 60 Hz

1x115V 60 Hz

Busbar 2

Busbar 3

460/230V

HF Gen2

HF Gen3

CalrodHeater

ChimneyHeater

HF Gen1

K110.3

K110.1

A110.6

T40.1 460/115V

T100.1

A20.2

M15.3

24VDC2x

12VDC

~ ~

A20.4 A20.6 E40.3 E50.5

K110.4 K110.5 K180.2 K190.1

M

Forepump1

Forepump2

K130.8 K121.8

M15.1 M15.3

M M

M M

CryoCompr. 1

CryoCompr. 2

A15.7 A15.8

M M

Hazard

ous

Appara

ture

sG

enara

lS

upply

3P+E / 3x460V 60 Hz

K 111.7K 111.8

Monitor

KH

AN

Printe

r

Fan

~

~

=

=UPS

Customer3 x 208 V

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3.8.2 Safety

The BAK 1131 features two safety related circuits:

� Safety circuit Emergency Off - When an emergency off button is pressed every sys-tem component is switched off redundantly. All emergency off buttons interrupt the circuit and can only be restored to the ON position by manually unlocking them. After pressing the blue reset button, which is located on the power distributor door above the main switch, all components that have been switched off are reactivated auto-matically unless an additional software command is required for this purpose.When the process chamber door is opened every system component that represents a potential hazard is switched off redundantly. The PNOZ 10 emergency stop device is also wired redundantly, that is, if one relay fails all safety requirements are still met. The safety cut-out on the process chamber door interrupts the circuit. After closing the process chamber door all components that have been switched off are reactivat-ed automatically unless an additional software command is required for this purpose.

� Handling Emergency Stop - When the emergency stop button is pressed the han-dling system is switched off redundantly. The PNOZ 10 emergency stop device is also wired redundantly, that is, if one relay fails all safety requirements are still met. All emergency stop buttons interrupt the circuit and can only be restored to the ON position by manually unlocking them. For restarting the handling system a reset but-ton must be pressed which is located on the right-hand side of the cleanroom-key-board.

No audible alarm signal is generated when an emergency stop of the BAK 1131 is per-formed.

Fig. 3-32 Position of the safety switches for the BAK 1131 (example)

A Emergency offB Emergency stopC Door switch

AA

A

A

A

B

C