A PHD Candiate from Michigan Tech University asks the following:
I need some conductive silicon wafer as substrate for CVD, and also I wish it can be etch resistant to KOH if possible. Do you have suggestions on the selection of your product?
I'm planning to use this wafer (150mm Silicon) for CVD growth of MoS2, and then use the as-grown sample to do electrochemical test. Therefore, I need the wafer to have good conductivity, even after exposure to ambient conditions.
Do you have some recommendations to my application?
We recomended the following Si wafer options:
Dia | Type/Dop | Ori | Res ohm-cm | Thick | Polish | Comments |
---|---|---|---|---|---|---|
150mm | N/As | (100) | 0.001-0.005 | 675μm | SSP | LTO Backside |
150mm | P/B | (100) | 0.001-0.005 | 675μm | DSP | 1Flat |
150mm | P/B | (100) | 0.01-0.02 | 675μm | SSP | 1Flat |
150mm | N/Sb | (100) | 0.008-0.020 | 675μm | SSP | 1Flat |
150mm | N/As | (111) | 0.001-0.005 | 675μm | SSP | 1Flat |
If you are to use these for CVD deposition of MoS2, then do you expect to create monocrystalline MoS2? If so then perhaps crystallographic orientation of the substrates are significant to you and you should specify them.
Silicon is not resistant to KOH etch. In fact MEMS manufacturing consists of etching Silicon wafers in KOH. You can grow SiO2 layer on Silicon which will make it somewhat resistant to KOH. You can coat the wafers with Silicon Nitride and then it will be very resistant to KOH. We can sell any of above listed wafers coated with either SiO2 or Si3N4 films.
Electrical conductivity is a property of internal bulk material, so it is not affected by corrosion of the surface. On the other hand, if you are concerned with providing good electrical ohmic contact to the Silicon wafer and the MoS2 layer, then that is another matter. We can supply above wafers with Ohmic contact to a thin gold or copper or aluminium layer.
Please specify what you need and we will be please to quote a price.