1. 2. Introduction to Design Rules
Etienne Sicard

2. Summary 1. Why confidentiality 2. Lambda based design
3. Basic design rules
4. Interconnect design rules
5. Supply design rules
6. Conclusion
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E. Sicard - Design rules

3. 1. Why Confidentiality Extremely strict in the past
Non-disclosure agreement
No copy
but
Most info is available on the web
SIA roadmap predict rules for the next 10 years
The document includes specific advances and weaknesses of the technology
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4. 2. Lambda based design Layout drawn on an integer grid
Grid unit fixed to  = half of technology forever
Poly gate = 2 
0.12µm,  = 0.06µm
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5. 2. Lambda based design  Good points Enables technology changes
Enable design reuse
Reduce design cost
 Bad points
Not optimal design
Rarely used in industry
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E. Sicard - Design rules

6. 3. Basic design rules 4 N-channel MOS 6 6 N+ 3 Metal 2
Not optimal but design reuse
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7. 3. Basic design rules P-channel MOS P+ 6 2 N+ 3 nwell 2N+ 3
nwell 2
No floating well
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8. 3. Basic design rules Inverter with same nMOS and pMOS sizes
pMOS carriers are twice slower than nMOS carriers
Demo
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9. 3. Basic design rules Minimize spared diffusion
Use minimum poly width (2)
1 contact = 1mA
Multiply contacts
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10. 3. Basic design rules Same N and P alters symmetry L min Wpmos=2 Wnmos
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11. 3. Basic design rules 2 metal 3 metal Supply in metal 3
Use stacked vias
Routing strategy metal 2 vertical, metal 3 horizontal
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12. 3. Basic design rules Design Rule Checker 12/4/2018
E. Sicard - Design rules

13. 4. Interconnect design rules
Up to 6 metal layers
Metal 2,3,4 identical
Metal 5,6 thicker, larger to be used for supply and long routing
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14. 4. Interconnect design rules
Demo
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15. 5. Supply design rules Aluminum is sensitive to electro-migration
metal 2,3,4: 1.5mA/µm
metal 5,6: 3 mA/µm
contact, vias: 1mA
1% fail in 20 years, 125°C
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16. Conclusion Confidentiality protects advances and weaknesses
Lambda-based design features easy reuse
Basic rules investigated
Interconnect design rules described
Power supply design rules introduced
Illustration made for 0.12µm
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