1. (4) S3.1

2. (3) What is the required dose for the same question if the oxide thickness is 1 nm?

3. (16) S3.2

4. (20) Using the example worked in class, (to=1.5 nm, N_A=3x10¹⁷, p+ gate doped at 3x10¹⁹):

a. Compare the threshold for n+ and p+ gates doped at 3x10¹⁹.

b. Same but for a PMOS transistor with the same doping levels.

c. What is the influence on the threshold voltage of fixed charge at the levels of 1x10¹⁰, 1x10¹¹, and 1x10¹² q/cm²? (This roughly spans the range from the minimum to the maximum expected value of fixed charge for different processes.)

d. Ignoring the effect of charge, what implant doses would be required to achieve +/- 0.3V thresholds for the NMOS and PMOS transistors (4 transistors, 2 NMOS, 2 PMOS, from above.) (Note that it is desirable to keep the threshold adjustment implant as small as possible, but generally less than about 1x10¹³ cm-2.)

5. (6) 7.2 (Note that metal gates are back!!)

6. (8) 7.4

7. (4) 7.9

8. (8) 7.10