Engineering Answers

(3) The transfer characteristic of MOS transistor is the dependence of ( ). 

A. Drain voltage on gate-source voltage B. Drain voltage on drain-source voltage

C. Drain current on drain-source voltage D. Drain current on gate-source voltage

(4)The drain of an n-channel MOSFET is shorted to the gate so that VGS = VDS. The 

threshold voltage (VT) of the MOSFET is 1 V. If the drain current (ID) is 1 mA for 

VGS = 2 V, then for VGS = 3 V, ID is ( ). 

A. 2 mA B. 3 mA C. 9 mA

(1) An NMOS transistor starts to conduct when the potential difference between

( ) is higher than the threshold voltage VT.

A. the drain and the source terminals B. the gate and the source terminals

C. the gate and the drain terminals D. the drain and the base terminals

(2) Which of the following is NOT true? ( ).

A. QOX is a function of applied gate voltage.

B. Threshold voltage is a function of tox.

C. P+ Poly silicon gate is usually used for n-MOS capacitor.

D. Once the strong inversion occurs, Qd (=the depletion charge) is approximately

unchanged with VGS.

Consider an n+-poly-Si-gated n-MOSFET with substrate dopant concentration NA = 

1016 cm-3, gate-oxide thickness tox = 0.12 μm, and Qox/q = 9 × 1010 cm-2. Calculate 

the threshold voltage, VT, of the MOS transistor.

Consider an n-channel MOSFET with W = 15 μm, L = 2 μm, and COX = 6.9×10-8

F/cm2. Assume that the drain current in the linear region for VDS = 0.10 V is IDS = 35 

μA at VGS = 1.5 V and IDS = 75 μA at VGS = 2.5 V. Determine the inversion carrier 

mobility and the threshold voltage from experimental results.

Consider an n+-poly-Si-gated long-channel n-MOSFET with W/L = 10, effective 

gate-oxide thickness Toxe = 2 nm, and substrate (body) dopant concentration NA = 

1018 cm-3. εSi02 = 3.9, εSi = 11.9. 

(1) Calculate the body effect parameter, γ. 

(2) How can the body effect be minimized?

3. Store the function y= x^2+2 in a 4*4 M ROM.

2. Draw the architecture of an 18 * 8 ROM.

1. Draw the architecture of a 16 * 10 ROM. What is the selected register when address is 1101?