I am trying to create a hetero-junction between GaAs and Si devices, but as you know there is a huge lattice mismatch between these two materials and thus ordinary hetero-epitaxial methods are not applicable. is there any method or buffer layers available to solve this problem?
I think you can use Ge instead of silicon. It matches GaAs to a great extent according to the paper in the link: Article III-V Multijunction Solar Cells for Concentrating Photovoltaics
As a proposal you can dope silicon with germanium heavily such that you can reduce the matching between silicon and GaAs.
Either you can use GaP or AlP instead of Ga As. This solution is extracted from the figure in the paper of the link:
Band gap and lattice constant for various III–V and group-IV material alloys.
Best wishes
Thank you very much dear Dr. Abdelhalim Zekry ,
I dont know how Si doping with Ge is done,
I also looked at the figure in the paper, AlP and GaP are actually lattice matched with silicon but again there is the difference between their lattice constants and GaAs and thus cannot be used an intermediate layer.
Sincerely,
Morteza
It is possible to grwo GaAg on Si, but there will be some induced stress and disorder in the process, which varies with the increase thickness of the Si GaAs layer. For example see: Article Raman Scattering by Epitaxial GaAs on a Si Substrate
Dear Dr Bahram Roughani ,
I am really grateful for your answer and I checked your interesting paper,
yet, I am trying to find a way to reduce the strain and disorder you mentioned.
Sincerely,
Morteza
Mr. Morteza Ahmadi,
Some of the approaches for reducing lattice mismatch induced stress, dislocations created by strain reduction, and anti-phase domains are to experiment with off-axis cut Si substrate, adding a buffer layer (e.g., GaAs based such as GaP, InGaAs, or possibly AlGaAs layers), and post growth annealing. See for example:
https://optoelectronics.ece.ucsb.edu/sites/default/files/2019-03/vegaflick19prm.pdf
http://www.semiconductor-today.com/news_items/2018/jan/ucsb_230118.shtml
Thank you very much Bahram Roughani
The resources you introduced were realy helpful.
It can be done via an oxide layer - there are commercial services doing such bonding and selling relevant tools, for example EVG
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