M.Sc. (Semester IV) (CBCS) Examination Mar/Apr-2018
Physics (Materials Science)
MICROELECTRONICS
Time: 2½ Hours
Max. Marks: 70
Instructions: Q. and are compulsory. Answer any three questions from Q.3 to Q.7. All questions carry equal marks. Use of nonprogrammable calculator is allowed.
Q.1
Select the most correct alternative.
14
For microelectronic applications, growth of single crystal Si along is favored.
110
100
101
111
The effective impurity concentration for a reliable diffusion of boron in Si is atoms cm3.
1019
1018
1020
1021
Molecular Beam Epitaxy is a process.
CVD
Non-CVD
PVD
VPE
In MOS-devices, the gate electrode used is usually
Polysilicon
Single Crystal Silicon
Multilayered Silicon
Stoichiometric Nitrides
Poly-Si deposition using CVD follows behavior.
Arrhenius
Ohmic
Kirchooff's
Exponential
Out of the following oxide charges, which are the orientation dependent?
Fixed Oxide Charges
Interface Trapped Charges
Mobile Ionic Charges
Oxide Trapped Charges
Al forms a contact with Silicon.
Non-Ohmic
Ohmic
Abrupt
Rectifying
Glassivation is usually done by
CVD
CBD
ECD
MBE
Which Photoresist is specially developed for LSI VLSI circuit fabrication
Iso-fine Kodak-820
Novolac
Hunt-way HPR-256
Iso-fine-Kodak-280
10) In a constant source diffusion, surface concentration is always
Decreasing
Increasing
Constant
Both and
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SLR-UN-488
11) Fick's first law of diffusion is expressed as
j=D∂N/∂x
-∂2N/∂x2
-D∂N ∂x
∂x
12) is used as a selective mask for oxidation of Si.
Si3N4
SiO2
Si2N3
SiN3
13) Si3N4 forms a Zero stress material with
SiO2
Si2O3
Si3O4
SiN3
14) Glue layer in metallization is the, reduction of
W
AI
Mo
Ti
Q.2
Write a note on. (Any Three)
14
Etch back effect
Substitutional diffusion
Multilevel metallization
Oxide charges
Q.3
Give a brief account of Vapor Phase Epitaxy for the growth of single crystal silicon.
10
What is a negative Photoresist?
04
Q.4
State and Explain Fick's 1st law of diffusion.
10
Explain in brief an interstitial diffusion.
04
Q.5
Discuss in brief the Molecular Beam Epitaxy for the epitaxial growth of Si.
10
Mention the salient feature of MBE over CVD.
04
Q.6
What is Oxidation? Discuss Deal and Groves model for kinetics of Si-Oxidation.
14
Q.7
Give an account of gas source system for diffusion of Boron in Silicon.
10
Write a note on wire bonding.