Dear all,
I am not chemist and I can't really find the answer to my question in the litterature.
Could anybody suggest me a recipe for a non-selective wet etching of InGaAs and InP with similar etch rates? If possible I would like to avoid Brome based mixtures.
I was wondering if mixing in the same solution mixtures of H2SO4:H2O2:H2O (etching InGaAs) and HCl:H2O (etching InP) would do the trick. Any chemist could confirm?
Thanks a lot for your help.
Thibault
Actually this info is in review by Clawson [A.R. Clawson / Materials Science and Engineering 31 (2001) 1] on p.17
HCl:HNO3 (1:2); equal etch rate on InP and InGaAsP 0:16 mm/s; Ref. (Furuya, K., 1981)
HBr:H3PO4:K2Cr2O7 (2:2:1); InP and InGaAsP equal etch rate 1:5 mm/min; does not attack photoresist; Ref. (Adachi, S., 1982a)
HBr:CH3COOH:K2Cr2O7 (1:1:1); InP and InGaAs mesa etch, equal rates for both; Ref. (Frei, M.R., 1991)
HBr:CH3COOH:K2Cr2O7 (2:2:1); nearly equal etch rate 2:5 mm/min for InGaAsP and InP.
I indeed saw this paper, but on one side I can't use brome based recipes, and on the other side, I tried the HCl:HNO3 solution but it does not etch (at least my) InGaAs at all. I came to the conclusion that this recipe attacks P sites and it doesn't work when there is no P in the matrix...
Thanks anyway for your answer.
Thibault
To avoid using brome based solutions I also was looking for alternatives. I used HCl:HNO3 solution and it worked for me in InP/InGaAs/AlInAs heterostructures, but the etching rate at room temperature was too high (I needed to decrease T down to 5 degrees) and the surface after 8 um etch was poor quality. Fortunately using this solution as a final step after etching in selective solutions gives nice shape of etched mesa.
- Badges
- Science topic
- Similar topics
- Chemistry