1. BICMOS TECHNOLOGY

2. TALK FLOW What is VLSI What is BiCMOS FEATURES
CHARACTERSTICS OF CMOS, BIPOLAR and BICMOS TECHNOLOGY
BiCMOS fabrication process
CMOS inverter
BiCMOS inverter
Comparison between CMOS and BiCMOS
Pros and Cons
Applications
Conclusion

3. What is VLSI ?
VLSI stands for very large scale integration and is the process of creating integrating circuits by combining thousands of transistors into a single chip.
Invention of VLSI is based on the achievements in the field of semiconductor technology.
Transistors were invented at Bell labs in
Jack kilby at texas instruments in 1958 was first to make a integrated circit ready.
It elimnates the use of discrete components, wires and manual assembly of components.
Eg. Microprocessor,controllers etc.

4. WHAT IS BiCMOS BiCMOS Bipolar compatible CMOS(BiCMOS) technology:
Introduced in early 1980s
Combines Bipolar and CMOS logic
CMOS BIPOLAR
Low power dissipation High speed
High packing density High output drive
BiCMOS

5. Features:
The objective of the BiCMOS is to combine bipolar and CMOS so as to exploit the advantages of both the technlogies.
Today BiCMOS has become one of the dominant technologies used for high speed, low power and highly functional VLSI circuits.
The process step required for both CMOS and bipolar are almost similar
The primary approach to realize high performance BiCMOS devices is the addition of bipolar process steps to a baseline CMOS process.
The BiCMOS gates could be used as an effective way of speeding up the VLSI circuits.
The applications of BiCMOS are vast.
Advantages of bipolar and CMOS circuits can be retained in BiCMOS chips.
BiCMOS technology enables high performance integrated circuits IC’s but increases process complexity. .

6. Characterstics of Bipolar Technology
Higher switching speed
Higher current drive per unit area, higher gain
Generally better noise performance and better high frequency characteristics
Improved I/O speed (particularly significant with the growing importance of package limitations in high speed systems).
high power dissipation
lower input impedance (high drive current)
low packing density
low delay sensitivity to load
It is essentially unidirectional.

7. Charactestics of CMOS Lower static power dissipation
Higher noise margins
Higher packing density
High yield with large integrated complex functions
High input impedance (low drive current)
Scaleable threshold voltage
High delay load sensitivity
Low output drive current (issue when driving large capacitive loads)
Bi-directional capability (drain & source are interchangeable)
A near ideal switching device
Low gain

8. Characterstics of Bicmos Technology
It follows that BiCMOS technology goes some way towards combining the virtues of both CMOS and Bipolar technologies
Improved speed over purely-CMOS technology
Lower power dissipation than purely-bipolar technology(Lower power consumption than bipolar)
Flexible I/Os for high performance
Improved current drive over CMOS
Improved packing density over bipolar
High input impedance
Low output impedance
High Gain and low noise

9. BiCMOS FABRICATION PROCESS
CMOS process
BIPOLAR process
1 . N well
1. n collector
2. P base doping(extra step)
3. PMOS source and drain
3. p+ base contact
4. NMOS source and drain
4. n+ emitter
Adapted from A.R.Alvarage et al.,”An overview of BiCMOS Technology and Applications”,IEEE International Symposium on Circuits and Systems,1-3 May,1990

10. BiCMOS CROSS-SECTION
Adapted from J. M Rabaey, Digital Integrated Circuits: A Design Prespective, NewJersey: Prentice-Hall, Inc., 1996.

11. BiCMOS process flow steps:

18. CMOS INVERTER CIRCUIT DIAGRAM VDD IP OP GND
Adapted from www2.eng.cam.ac.uk/~dmh/3b2/invert.htm

19. BASIC BiCMOS INVERTER
Adapted from J. M Rabaey, Digital Integrated Circuits: A Design Prespective,New Jersey: Prentice-Hall, Inc., 1996.

20. CONVENTIONAL BiCMOS INVERTER
Adapted from J. M Rabaey, Digital Integrated Circuits: A Design Prespective,New Jersey: Prentice-Hall, Inc., 1996.

21. PULL UP EVENT
C load
Adapted from Sung-Mo Kang,Yusuf Leblebici,”CMOS Digital Integrated Circuits:Analysis and Design”,Tata McGraw-Hill,Third edition,2003,p.547.

22. PULL DOWN EVENT
C load
Adapted from Sung-Mo Kang,Yusuf Leblebici,”CMOS Digital Integrated Circuits:Analysis and Design”,Tata McGraw-Hill,Third edition,2003,p.550.

23. BiCMOS VS. CMOS VTC comparison CMOS BiCMOS
Nfbdf,fmnsdvnv,sndkmvnmdnvn,fnv
BiCMOS
Adapted from www2.eng.cam.ac.uk/~dmh/3b2/invert.htm

24. SPEED COMPARISON
Adapted from Larry Wissel and Elliot L. Gould,”Optimal Usage of CMOS within a BiCMOS Technology”,IEEE J. of solid-state circuits, Vol. 27, No. 3, March1992

25. DELAY COMPARISON scaling of the technological parameters leads to the scaling of the device parameters
Adapted from Larry Wissel and Elliot L. Gould,”Optimal Usage of CMOS within a BiCMOS Technology”,IEEE J. of solid-state circuits, Vol. 27, No. 3, March 1992

26. AREA COMPARISON A AREA C COMPLEXITY
Adapted from H.Klose et al.,”Bicmos,a tehnology for High speed/High density ICs”,IEEE international conference on Computer Design:VLSI in computers and proessors,2-4 Oct.,1989

27. PROS OF BiCMOS Improved speed over CMOS
Improved current drive over CMOS
Improved packing density over bipolar
Lower power consumption than bipolar
High input impedance
Latchup immunity

28. CONS OF BiCMOS Increased manufacturing process complexity
Speed degradation due to scaling
The efficiency of BiCMOS device increased by 2 and cost increased by 1.3 to 1.5 as compared to CMOS.
Adapted from Paul G. Y. Tsui et al.,”Study of BiCMOS Logic Gate Configurations for Improved Low-Voltage Performance”, IEEE J. of solid-state circuits, Vol. 28, No 3. March 1993.

29. APPLICATIONS Full custom ICs Semi custom ICs Standard cells
SRAM,DRAM
Microproessor,controller
Semi custom ICs
Register,Flipflop
Standard cells
Adders,mixers,ADC,DAC
Gate arrays

30. BiCMOS PRODUCTS W-CDMA DCR GSM 900 POWER AMPLIFIER
SiGe BiCMOS GPS CIRCUIT
W-CDMA DCR

31. CONCLUSION
The extra process complexity requires chip manufacturers to command a premium for BiCMOS products. In the analog market the ability to integrate large mixed systems provides the compelling cost advantage of BiCMOS; this market is still emerging.
BiCMOS is a complement to pure CMOS and Bipolar technologies in important system application areas.
One of the main challenges facing BiCMOS design is to maintain its performance gain at lower voltage levels.

32. REFERENCES
[1]Kiat-Seng Yeo et al.,”CMOS/BiCMOS ULSI:Low voltage,Low power”,Pearson Education,Inc., First edition,2002.
[2]Sung-Mo Kang,Yusuf Leblebici,”CMOS Digital Integrated Circuits:Analysis and Design”,Tata McGraw-Hill,Third edition,2003.
[3]E.A.Gonzalez,”BiCMOS processes,trends and applications”,DLSU ECE,Technical report,Nov.29,2004.
[4]A.R.Alvarez et al.,”An overview of BiCMOS technology and applications”,IEEE International Symposium on Circuits and Systems,1-3 May,1990.
[5] T. Sakurai, “A review on low-voltage BiCMOS circuits and a BiCMOS vs. CMOS speed comparison,” Proceedings of the 35th Midwest Symposium on Circuits and Systems, vol. 1, Aug
[6] J. M Rabaey, Digital Integrated Circuits: A Design Prespective, NewJersey: Prentice-Hall, Inc., 1996.
[7] J. P. Uremuya, Circuit Design for CMOS VLSI, Massachusetts: Kluwer Academic Publishers, 1992.
[8] Adapted from H.Klose et al.,”Bicmos,a tehnology for High speed/High density ICs”,IEEE international conference on Computer Design:VLSI in computers and proessors,2-4 Oct.,1989
[9] Larry Wissel and Elliot L. Gould,”Optimal Usage of CMOS within a BiCMOS
Technology”,IEEE J. of solid-state circuits, Vol. 27, No. 3, March 1992
[10] Paul G. Y. Tsui et al.,”Study of BiCMOS Logic Gate Configurations for Improved Low-Voltage Performance”, IEEE J. of solid-state circuits, Vol. 28, No 3. March 1993.
[11] D.L.Harame,”Current Status and Future Trends of SiGe BiCMOS Technology” IEEE transactions on electron devices, vol. 48, no. 11, november 2001
[12]Adapted from D.Harame et al.,”The Emerging Role of SiGe BiCMOS Technology
in Wired and Wireless Communications”, Fourth IEEE International Caracas Conference on Devices, Circuits and Systems, Aruba, April 17-19, 2002.

33. THANK YOU
Q U E R I E S ?