VLSI TECHNOLOGYSEM-VI, 2014B.TECH EXAMINATIONUTTARAKHAND TECHNICAL UNIVERSITY (UTU)
Time: 3hours
Total marks: 100
Q1. Attempt any Four:
A. Describe and discuss various features
of ICs with respect to discrete integral circuits.
B. What are the various steps involved in
the manufacturing of monolithic IC.
C. Why oxidation is done? Explain the
chemistry of oxidation and kinetics of oxide growth.
D. A silicon wafer with p type doping of
1015 is heated at 1000⁰ C for 1 hour in day oxygen. How much
oxide has been grown?
E. Describe a CZ furnace. What are its
advantages?
F. All modern silicon MOSFET’s are
fabricated on <100> oriented Si substrate. Why?
Q2. Attempt any four:
A. What are the process variables which
affect the diffusion process? Explain.
B. What is optical growth? What is the
advantage of epitaxial process over diffusion and Czo kralski process?
C. What is Fick’s Law? Explain it’s
important in theory of diffusion.
D. What is the MBE system? Explain with
diagram.
E. Write short note on
i.
Photo
mask and photo resist.
ii.
Photo
lithography techniques.
F.
Does
the thickness of the epitaxial wafer pose a problem in epitaxial processing
from a stress view point? Discuss your answer.
