21. Design rule is not influenced by the maturity of the property line.
A. true
B. false
Answer: A
Design rules can also be influenced by the maturity of the process line. If the process is mature, then one can be assured of the process line capability allowing tighter design with fewer constraints.
22. The separation between implants is determined from
A. width of the transistor
B. width of E-MESFET
C. width of D-MESFET
D. width of the photoresist
Answer: D
The separation between implants is determined by the width of the depletion region and the width of the photoresist.
23. MESFETs should be positioned
A. horizontally
B. vertically
C. diagonally
D. randomly
Answer: A
All MESFETs should be positioned horizontally owing to the anisotropic nature of GaAs which influences the threshold voltage of the device.
24. Saturated resistor is a
A. FET with schottky gate
B. FET without Schottky gate
C. MESFET with schottky gate
D. MESFET without Schottky gate
Answer: D
The saturated resistor is a MESFET with the Schottky gate removed. The preferred direction for layout is vertical.
25. MIM capacitor uses
A. metal 1
B. metal 2
C. metal 1 and metal 2
D. Schottky gate
Answer: C
The metal-insulator-metal (MIM) capacitor structure is simple using metal 1 and metal 2 as the plates of a parallel plate capacitor.
26. The mask is derived from the structural operation of masks.
A. true
B. false
Answer: B
The mask is derived from the logical operation of the active layer masks. Some processes require isolation between devices to reduce their interaction.
27. Normally-on logic uses
A. depletion mode MESFET
B. enhancement mode MESFET
C. depletion-mode FET
D. enhancement mode FET
Answer: B
Normally-on logic uses depletion-mode MESFETs which are ON devices and when used as switching elements are required to be turned OFF.
28. Which is the approach used for normally-off logic?
A. capacitor diode FET logic
B. buffered FET logic
C. direct-coupled FET logic
D. capacitor coupled FET logic
Answer: C
The approaches used for normally-off logic are direct-coupled FET logic, buffered DCFL, and source-follower DCFL.
29. __________ is needed to facilitate turn-off.
A. positive voltage
B. power supply rail
C. ground connection
D. negative voltage
Answer: D
Since D-MESFETs are ON devices, a negative voltage is needed at the gate to facilitate turn-off.
30. __________ supply rails are required for proper operation of normally-on logic devices.
A. one
B. two
C. three
D. four
Answer: B
Two supply rails together with level shifting networks are necessary for proper circuit operation of normally-on logic gates.