VLSI Design Mid - I, September - 2014

1.In the p-well process of CMOS fabrication ___________ substrate is used.
  • P-type
  • N-type
  • C-type
  • none
Answer: A
2.Main drawback of BICMOS technology
  • Low speed
  • Higher power dissipation
  • High cost
  • High speed
Answer: C
3.Steps involved in manufacturing of IC
  • Oxidation
  • Photolithography
  • Ion implantation
  • all
Answer: D
4.________ is ideally suited for applications using battery power or battery backup power.
  • MOS
  • P-MOS
  • N-MOS
  • CMOS
Answer: A
5.Identify different CMOS technologies
  • N-well process
  • P-well process
  • Twin-tub process
  • all
Answer: D
6.VLSI means
  • a device containing transistors between 103 and 105
  • a device containing transistors between 105 and 107
  • a device containing transistors between 103 and 104
  • a device containing transistors between 105 and 109
Answer: B
7.Latch up problems occurs in CMOS circuits due to
  • Parasitic capacitance
  • Parasitic bipolar transistors
  • Parasitic resistance
  • none
Answer: B
8.Switching behaviour of MOS Transistor is characterized by __________
  • Threshold voltage
  • Doping
  • Drain voltage
  • Substrate
Answer: A
9.Which of the following statements is incorrect?
  • CMOS circuitry is more difficult to fabricate than NMOS or PMOS as it required devices of both polarities.
  • CMOS gates have very good noise immunity that is typically 10% of the supply voltage.
  • When a CMOS gate is static it has negligible power consumption.
  • CMOS gates have logic levels close to the supply rails
Answer: B
10.The ________ has a physical channel between the drain and source.
  • D-MOSFET
  • E-MOSFET
  • V-MOSFET
  • None
Answer: A
11.The five basic chemical reactions pyrolosis, photolysis,reduction, oxidation or reduction-oxidation can be used in __________________
Answer: Chemical vapour deposition
12.Material used for metallization is _________________
Answer: Silver
13.Material used for gate oxide in MOS technology is _______________
Answer: SiO2
14.Impurity used in diffusion _______________
Answer: B2O3
15.In p-well CMOS fabrication ______________ well is formed.
Answer: P-well
16.Based on ______________ law number of transistors doubles for every 18 months.
Answer: Moore’s law
17.CMOS transistor is combination of ____________________ transistors.
Answer: N-MOS, P-MOS
18.Input impedance of MOS Transistor _________________ compared to BJT.
Answer: HIGH
19.Steps involved in twin tub process ________________
Answer: Tub Formation, Thin-oxide Construction, Source & Drain Implantation
20.__________________ are different types of MOSFET.
Answer: Enhancement type, depletion type