stacking process
DESCRIPTION
Stacking Process. < Optical Micrograph >. < Scanning Electron Micrograph >. 3 rd Si thinned to 5.5um. 2 nd Si thinned to 5.5um. SiO 2. 1 st Si bottom supporting wafer. “Super Via” 4um in diameter and 12um in height. Three wafers successfully aligned and stacked. 3 rd Si - PowerPoint PPT PresentationTRANSCRIPT
Tezzaron Semiconductor
Tezzaron Semiconductor
Stacking Process
< Optical MicrographOptical Micrograph > < Scanning Electron MicrographScanning Electron Micrograph >
“Super Via” 4um in diameter and 12um in height
3rd Si thinned to 5.5um
2nd Si thinned to 5.5um
1st Si bottom supporting wafer
SiO2
Three wafers successfully aligned and stacked
Tezzaron Semiconductor
3rd Si2nd Si
1st Si
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1.2 um1.2 um
Profiler View
Microscope View
Wet Etch: 1.2 µm Copper Via protruding
CuCu
SiSi
SiO2SiO2
SiSi4.8 um4.8 um
2 um2 um
2 um2 um
11stst wafer wafer
22ndnd wafer wafer
Exposed Bottoms of Super Vias
Tezzaron Semiconductor
11stst Wafer Blanket Cu Wafer Blanket Cu
33rdrd Wafer Blanket Cu Wafer Blanket Cu
2nd Wafer pattern Cu2nd Wafer pattern Cu
Super ViaSuper Via
Top MetalTop MetalPadPad
Three Cu Wafer Stacking
Three wafers stacking using an alternative stacking architecture “stacking process without backside process” invented during this project time, has been successfully demonstrated.
FIB micrograph showing 3 stacked wafer using newly designed process flow
Tezzaron Semiconductor
Tezzaron Semiconductor
Reg. File / Mixed Signal ASIC
• Byte per layer dual port memory• Bandgap on each layer• Heater Resistor to induce stress • 133MHz DLL (DDRI/II)• 4 Stage charge pump (cross layer)• POR
Tezzaron Semiconductor
Register File
Tezzaron Semiconductor
CPU/Memory Stack
• R8051 CPU – 80MHz operation; 140MHz Lab test (VDD High)– 220MHz Memory interface
• IEEE 754 Floating point coprocessor• 32 bit Integer coprocessor• 2 UARTs, Int. Cont., 3 Timers, …• Crypto functions• 128KBytes/layer main memory
• Completely synthesized, placed and routed in 3D with standard Cadence tools. Runs slightly better than predicted by models and tools.
Tezzaron Semiconductor
R8051/Memory