21. Which color is used to represent first-level metal?
A. brown
B. blue
C. dark blue
D. green
Answer: B
Blue (metal 1) is used to represent first-level metal and dark blue (metal 2) is used for second-level metal.
22. The _______ mask identifies all active regions.
A. blue layer
B. red layer
C. yellow layer
D. green layer
Answer: D
The green layer mask identifies all active regions such as areas that eventually form E and D type devices, active loads, and implant resistors.
23. ______ forms the more heavily doped channel of D-MESFET.
A. red inside yellow layer
B. green inside yellow layer
C. yellow inside green layer
D. green outside yellow layer
Answer: B
The green region inside the yellow layer mask forms the more heavily doped channel of the D-MESFET.
24. _______ is used to represent the lightly doped channel of E-MESFET.
A. red inside yellow layer
B. green inside yellow layer
C. yellow inside green layer
D. green outside yellow layer
Answer: D
Green regions outside the yellow layer from the lightly doped channel of the E type MESFET.
25. ______ is used to represent implant.
A. yellow
B. red
C. green
D. brown
Answer: C
The green color is used to represent the implant layer. Symbolically it is represented as E-MESFET and it is formed when crossed by gate-metal.
26. _____ is used to represent ohmic contact.
A. yellow
B. red
C. green
D. brown
Answer: D
Brown is used to representing ohmic contact and it is used with source/drain contacts.
27. In the ring diagram, the green line is used to represent
A. E-MESFET
B. D-MESFET
C. Interconnection
D. Transistor
Answer: A
In the ring diagram, a green or dotted line represents E-MESFET while a yellow or solid line represents D-MESFET.
28. E-type and D-type are joined together using
A. metal 1
B. metal 2
C. vias
D. interconnectors
Answer: A
E-type and D-type features are joined together using a blue color which represents metal 1 layer.
29. What is the intermediate stage in converting ring diagram to mask layout?
A. switch logic
B. transistor level diagram
C. symbolic diagram
D. stick diagram
Answer: C
The ring diagrams can be turned into mask layout directly or through an intermediate symbolic representation stage.
30. In symbolic representation, rings are converted into
A. color codes
B. switches
C. sticks
D. circuit elements
Answer: D
Symbolic representation is the intermediate stage when turning a ring diagram to mask layout and here rings are represented as circuit elements.
