In CMOS transistor P-mos is formed in

In CMOS (Complementary Metal-Oxide-Semiconductor) technology, a P-MOS (P-type Metal Oxide Semiconductor) transistor is formed in an N-well or N-tub. Here are the steps:

1. Start with a lightly doped N-type silicon substrate.
2. Create an N-well by implanting P-type ions into the substrate. The N-well will serve as the body for the P-MOS transistor.
3. Grow a thin layer of silicon dioxide (SiO2) over the entire wafer. This will serve as the gate oxide.
4. Deposit a layer of polysilicon over the SiO2 layer. This will serve as the gate electrode.
5. Use photolithography and etching processes to define the gate, source, and drain regions.
6. Implant P-type ions to form the source and drain regions of the P-MOS transistor.
7. Deposit a layer of SiO2 over the entire wafer and etch contact holes to the source, drain, and gate regions.
8. Deposit and pattern a layer of metal to form the interconnections.

The P-MOS transistor is now formed in the N-well. The source and drain are P-type regions, and the body is the N-type region. The gate is formed over the channel region between the source and drain, and is insulated from the channel by the thin SiO2 layer.