How to make PIN transistor

[sitangshu]

Hi,

     I want to make a silicon nanowire P+I N tunnel FET. The transport is along [100] direction. The problem is what should be the process of making a P+ (highly doped) in a Silicon using element like Boron and what should be the process of making a N-type doped using Arsenic on the other side.  I want a gate length of 30 nm with cross sectional area of 2X2 nm^2. Please also let me know the process of adding the metallic gate and the two metallic electrodes.

     I would be extremely grateful for your reply.

Thanks.

[kstokbro]

According to my estimate this will require 15000 atoms. You will need a large computer for this and I would recommend that you use ATK-SE.

May I suggest that you start som initial studies with a much smaller system. You can do the doping by substituting Silicon atoms with the doping elements.

[sitangshu]

Thanks for your answer. The problem is suppose I want a doping concentration of 10^6/m in a SiNW of length 10 nm. What should be the proper way? Should I replace Silicon in the unit cell itself and repeat the structure? Even if I do so , then how many Si atoms I have to replace to get such doping level.
Waiting for your reply.

Thanks
Sitangshu

[kstokbro]

10^6/m means one doping atom for each micrometer, thus there will be no doping atoms in a 10 nm wire.
Are you sure this is what you want?

[sitangshu]

Dear Sir,
Yes you are right, it is my mistake. What I meant to say that for 10^9/m. How will I do this? Would this doping concentration mean the system will be degenerate or non degenerate?
Waiting for your answer.

Thanks
Sitangshu

[kstokbro]

With 10^/9/m doping level, you will have one doping atom for each 1 nm, thus in a 10 nm long wire there should be 10 doping atoms.
The position of the doping atoms will be random and the average distance between the doping atoms will therefore be quite large, and the interaction between doping atoms neglectible. I will therefore expect that the doping levels will be degenerate.