Enlist steps for fabrication of CMOS inverter using the N well process. Draw a vertical cross-sectional view starting from the substrate to the gate, source, and drain formation in the fabrication of the CMOS inverter.

Solution:

cos inverter using the N-well process.

Step-1: n-well fabrication:

1. P-type substrate.

2. Grow $\mathrm{SiO}_2$

3. Apply photoresist

4. Use $N$-well mask Etch photoresist in window 5. Etch oxide. Use photo resists as a mask. Window formed in $\operatorname{SiO}_2$ 6. Etch photoresist. on the wafer 6. Etch photoresist. on the wafer. 7. Implant $N$-well.

5. Exh oxide.

Step 2: Deposit polysilicon and Gate formation.

1. Grow thin oxide and deposit poly.

2. Use Gate mask Exch Poly and thin oxide.

3. Grow thick oxide.

Step 3: Carry out n-diffusion bor nos and well contact

1. Etch oxide for n-mos and n-well contact n-diffusion:

1. n+ dibasic/implant.

1. Etch oxide.

Step 4: P Diffusion for Pmos and contact for the substrate.

1. P Diffusion-Grow thick oxide, Etch oxide, P-diffusion.