Copyright Prentice-Hall

Chapter 28Fabrication of Microelectronic Devices

Parts Made by Chapter 28 Processes

(a) (b) (c)

(a) A completed eight-inch wafer with completed dice. (b) A single chip in a ball-grid array (BGA) with cover removed. (c) A printed circuit board. Source: Courtesy of Intel Corporation.

Q18.2 (25) Point out the ball grid array in Figure 28.1.

Fabrication of Integrated Circuits

Outline of the general fabrication sequence for integrated circuits.

Fabrication of MOS (metal-oxide semiconductor) Transistor

Cross-sectional views of the fabrication of a MOS transistor. Source: After R. C. Jaeger.

Allowable Particle Size Counts for Clean Rooms

Allowable particle size counts for different clean room classes.

Crystallographic Structure and Miller Indices for Silicon

Crystallographic structure and Miller indices for silicon. (a) Construction of a diamond-type lattice from interpenetrating face-centered cubic-cells; one of eight penetrating cells is shown. (b) Diamond-type lattice of silicon; the interior atoms have been shaded darker than the surface atoms. (c) Miller indices for a cubic lattice.

Finishing Operations on a Silicon Ingot to Produce

Wafers

Finishing operations on a silicon ingot to produce wafers (a) sawing the ends off the ingot; (b) grinding of the end and cylindrical surfaces of a silicon ingot; (c) machining of a notch or flat; (d) slicing of wafers; (e) end grinding of wafers; (f) chemical-mechanical polishing of wafers.

CVD Diagrams

Schematic diagrams of (a) a continuous, atmospheric-pressure CVD reactor and (b) a low-pressure CVD. Source: After S. M. Sze.

Silicon Dioxide Growth

Growth of silicon dioxide showing consumption of silicon. Source: After S. M. Sze.

General Characteristics of Lithography Techniques

Comparison of lithography techniques.

Spinning of Organic Coating on Wafer

Spinning of an organic coating on a wafer.

Techniques of Pattern Transfer

Schematic illustration of (a) wafer stepper technique to pattern transfer and (b) step-and-scan technique.

Pattern Transfer by Photolithography

Pattern transfer by photolithography. Note that the mask in Step 3 can be a positive or negative image of the pattern.

Moore’s Law

Illustration of Moore’s law. Source: After M. Madou.

Etching Directionality

Etching directionality. (a) Isotropic etching: etch proceeds vertically and horizontally at approximately the same rate, with significant mask undercut. (b) Orientation-dependant etching (ODE): etch proceeds vertically, terminating on {111} crystal planes with little mask undercut. (c) Vertical etching: etch proceed vertically with little mask undercut. Source: Courtesy of K. R. Williams, Agilent Laboratories.

Application of Boron Etch Stop and Back Etching to Form Membrane and Orifice

Application of a boron etch stop and back etching to form a membrane and orifice. Source: After Brodie, I., and Murray, J.J., The Physics of Microfabrication, Plenum Press, 1982.

Machining Profiles Associated with Dry-Etching

Machining profiles associated with different dry-etching techniques: (a) sputtering; (b) chemical; (c) ion-enhanced energetic; (d) ion-enhanced inhibitor. Source: After M Madou.

Holes Generated from Square Mask

Various holes generated from a square mask in: (a) isotropic (wet) etching; (b) orientation-dependant etching (ODE); (c) ODE with a larger hole; (d) ODE with a rectangular hole; (e) deep reactive-ion etching; and (f) vertical etching. Source: After M. Madou.

Interconnection of Integrated Circuit Hierarchy

Connections between elements in the hierarchy for integrated circuits.

Two-Level Metal Interconnect Structures

(a) Scanning electron microscope (SEM) photograph of a two-level metal interconnect. Note the varying surface topography. (b) Schematic illustration of a two-level metal interconnect structure. Source: (a) Courtesy of National Semiconductor Corporation. (b) After R. C. Jaeger.

Wire Bonds Connecting Package Leads to Die Bonding Pads

(a) SEM photograph of wire bonds connecting package leads (left-hand side) to die bonding pads. (b) and (c) Detailed views of (a). Source: Courtesy of Micron Technology, Inc.

(a) (b) (c)

Thermosonic Welding of Gold Wires

Schematic illustration of thermosonic welding of gold wires from package leads to bonding pads.

IC Packages

Schematic illustration of various IC packages: (a) dual-in-line package (DIP); (b) flat, ceramic package; (c) common surface-mount configurations; (d) ball-grid arrays.

Circuit Board Structures and Features

Printed circuit board structures and design features.