mita_practical_course_of_gatearray.pdf

Practical Course of Design, Fabrication
and Testing of CMOS Gate Array
YOSHIO MITA, Satoshi Komatsu,
Makoto Ikeda, Minoru Fujishima,
and Kunihiro Asada
VLSI Design and Education Center
(VDEC), the University of Tokyo
[email protected]
Introduction
Š Education of VLSI is important
Š Learning of Electronics with Practical Experience
is specially emphasized.
Type
Title
Grade
Hour
Area
Lecture
Basics on VLSI Engineering
3rd
21hrs
General
Lecture
VLSI Design Engineering
4th
21hrs
Design
Lecture
Electronics Material Process
4th
21hrs
Process
Seminar
VLSI Layout and Simulation
3rd
18hrs
Backend
Seminar
C-Based Hardware Design
3rd
18hrs
Frontend
Practical
CMOS Gate Array Design and
Fabrication
3rd
30hrs
Backend to
Process
Gate Array Practical Course
Š Backend design - Process - Measurement
Process: 0.6um 1-layer Aluminum lithography & Etching
Schedule
Š 10-days’ course
Day
Group #1
Group #2
1st - 4th
Gate Array Design
5th
Visiting In-house Mask Fabrication Facility
6th
Process
Measurement Preparation
7th
Measurement I
Supplemental Study
8th
Measurement II
Supplemental Study
9th
Supplemental Study
Measurement I
10th
Supplemental Study
Measurement II
Design
Š at VDEC’s seminar room
Š 1st day: CAD literacy, 2nd -4th : Design Practice
Bulding Blocks
Š 7 x 7 = 49 building blocks
Š 3 common-gate PMOSFET and NMOSFET
Design procedure
Š Design (Virtuoso)
Š Circuit Extraction (DRACULA)
Š Simulation (HSPICE)
Examples on Year 2003
Š 2 students consist a group.
Š A group can: design individually, or in
collaboration
2bit full adder
7segment LED decoder
2bit ALU (Adder+Multiplier)
6bit adder
2bit comparator
Boolean function selector
2bit carry look ahead adder
Edge trigger JK-FF
3bit adder with memory
3input AND
Process
Š Cleaning + UV exposure (Shipley S1805)+
Etching (H3PO4 +CH3COOH+HNO3)
Fabrication Example
Š Inverter
Analysis practice
Š Question: measure delay time
Typical reply: Impossible, because frequency is low.
Input
Output
: Not many students can find that
they are allowed to magnify only
rising or falling period...
Š Students who designed too ambitious circuit:
Cannot obtain desired output.
: Not many students can find that wiring
width is large (50um) enough thus
direct probing is possible anywhere
Failure reasons..
Š Damaged sample (results open)
Š Particles (results short)
Š Under development/etching
Š Careless scratch (probing error)
.. Students can learn
typical failures in university laboratories.
Portability I
Š MASK fabrication is the key issue.
Portability II
Š Glass immersion mask is possible
Š 35mm reversal film could also be used.
Conclusions
Š 10-days’ practical course
Š Experience from Backend to Process
Š Maximum 40 out of 120 students can take
Š Students can acquire knowledge on practical
problems out of their computer world.