22. Implant should extend _______ from all the channels.
A. 2λ
B. 3λ
C. 4λ
D. λ
Answer: A
Implant for an n-mos depletion-mode transistor should extend a minimum of 2λ from the channel in all directions.
23. Which type of contact cuts are better?
A. buried contacts
B. butted contacts
C. butted & buried contacts
D. none of the mentioned
Answer: A
Buried contacts are much better than butted contacts. In butted contacts, the two layers are joined together or bound together using an adhesive type of material whereas in buried contact one layer is interconnected or fitted into another.
24. Which design method occupies or uses a lesser area?
A. lambda rules
B. micron rules
C. layer rule
D. source rule
Answer: B
Micron rules occupy or consume the lesser area. 50% of the area usage can be reduced by using micron rules over lambda rules.
25. Which gives scalable design rules?
A. lambda rules
B. micron rules
C. layer rules
D. thickness rules
Answer: A
Lambda rules give scalable design rules and micron rules give absolute dimensions.
26. Devices designed with lambda design rules are prone to shorts and opens.
A. true
B. false
Answers: b
Lambda design rules prevent shorting, opens, and contact from slipping out of the area to be contacted.
27. Diffusion and polysilicon layers are connected together using __________
A. butting contact
B. buried contact
C. separate contact
D. cannot be connected
Answer: A
Diffusion and polysilicon layers are joined together using butting contact. In butting contact, the two layers are joined or bound together
.
28. Which is a more complex process in VLSI?
A. buried contact
B. butting contact
C. buried & butting contact
D. none of the mentioned
Answer: A
Butting contact is a complex process whereas buried contact is a simple process because butting contact should be done more carefully to serve well and be strong.
29. Which contact cut occupies a smaller area?
A. buried contact
B. butting contact
C. buried & butting contact
D. none of the mentioned
Answer: A
Buried contact occupies a smaller area than butting contact as in buried contacts one layer will be completed within or almost within the other layer.
30. Isolation layer between two metal layers must be thinner.
A. true
B. false
Answer: B
The isolation layer between two metal layers should be thicker. Metal to metal separation is large and is brought about mainly by difficulties in defining metal edges accurately.
31. The oxide layer below the first metal layer is deposited using __________
A. diffusion method
B. chemical vapor deposition
C. solid deposition
D. scattering method
Answer: B
The oxide layer below the first metal layer is deposited using the chemical vapor deposition method. This is a chemical process used to produce high-quality high-performance solid materials.
