Nano tech : Photolithography Process

 Photolithography Process

Photolithography is a complicated process. Try to elaborate this Process simply........

At first, select a P - type or N - type material as a substrate. Here only consider a P - type material 

Then add the SiO₂ solution. The layer of SiO₂ is placed on the surface uniformly of the substrate.

 A positive photoresist is placed over the surface of the SiO₂ layer. Only positive photoresist is used in lithography process.

 A mask is designed and placed over the photoresist layer.

 UV light is applied on the mask.

Due to positive photoresist the portion of non mask area get soluble.

Now, etch the SiO₂ according to the photoresist pattern.

 Removed the positive photoresist from the surface of SiO₂ thin layer.

 Etch the substrate according to the pattern and pushed N - type  material to it. In case using N - type material as a substrate then have to push P - type material.