VLSI Multiple Choice Questions on “Stick Diagram”.
1. Stick diagrams are those which convey layer information through?
A. thickness
B. color
C. shapes
D. layers
Answer: B
Clarification: Stick diagrams are those which convey layer information through color codes. Thickness is not considered in this stick diagram representation.
2. Which color is used for n-diffusion?
A. red
B. blue
C. green
D. yellow
Answer: C
Clarification: Green color is used to show the presence of n-diffusion layer. The n-type diffusion will dope the source or drain region in the p-well region.
3. Which color is used for implant?
A. red
B. blue
C. green
D. yellow
Answer: D
Clarification: Yellow color is used to represent implant layer.
4. Which color is used for contact areas?
A. red
B. brown
C. black
D. blue
Answer: C
Clarification: Black color is used to represent contact areas. This is the part where two different touch or cross each other.
5. Which color is used for polysilicon?
A. brown
B. red
C. white
D. orange
Answer: B
Clarification: Red is used to represent polysilicon layers. It is a semi-conductor like material and is a hyper pure form of silicon.
6. Which color is used for polysilicon 2?
A. blue
B. brown
C. orange
D. white
Answer: C
Clarification: Orange color is used to represent polysilicon-2 layer.
7. Which color is used for buried contact?
A. black
B. white
C. green
D. brown
Answer: D
Clarification: Brown color is used to represent buried contact. Buried contact is most widely used, subject to fewer design rule restrictions are smaller in area.
8. n and p transistors are separated by using __________
A. differentiation line
B. separation line
C. demarcation line
D. black line
Answer: C
Clarification: Demarcation line separates n and p transistors. Demarcation line is similar to dotted line in brown.
9. _______ layer should be over ______ layer.
A. ntype, polysilicon
B. polysilicon, ntype
C. ptype, ntype
D. ntype, ptype
Answer: B
Clarification: Polysilicon layer should be over n-type layer. This is the standard pattern used in stick diagram representation.
10. How is nMOS depletion mode transistor represented?
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Answer: C
Clarification: nMOS depletion mode transistor can be represented by using polysilicon over ntype layer and with an implant.
11. Implant is represented using ___________
A. black, dark line
B. black, dotted line
C. yellow, dark line
D. yellow, dotted line
Answer: D
Clarification: Implant is represented using yellow color dotted lines. It is drawn in the middle of the nMOS or pMOS wherever the implant is used.
12. Stick diagram gives the position of placement of the element.
A. true
B. false
Answer: B
Clarification: Stick diagram does not show exact placement of components, transistor length, wire length and width, tub boundaries, etc.
13. When two or more cuts of same type cross or touch each other, that represents ____________
A. contact cut
B. electrical contact
C. like contact
D. cross contact