A wet etching technique for accurate etching of GaAs/AlAs distributed Bragg reflectors
- Stanford Univ., CA (United States). Solid State Labs.
The authors have demonstrated a wet etching technique capable of producing accurate and uniform etch depths in distributed Bragg reflectors (DBRs) and other GaAs/AlAs superlattice structures. The process utilizes two selective etchants, citric acid/hydrogen peroxide in a 4:1 ratio and phosphoric acid/hydrogen peroxide/water in a 3:1:50 ratio, to sequentially etch away each pair of superlattice layers. The authors have used this technique to expose a 680 {angstrom} thick conduction GaAs layer buried beneath a 15 period, 2.1 {micro}m thick, undoped GaAs/AlAs DBR mirror. Transmission line measurements pads were formed on the exposed layer to determine the contact and sheet resistance. Comparison with a similar layer on the surface of the wafer reveals that the exposed layer is easily contacted with only a slight increase in sheet resistance indicating less than 125 {angstrom} of overetching, 0.6% of the total etch depth.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 99623
- Journal Information:
- Journal of the Electrochemical Society, Vol. 142, Issue 7; Other Information: PBD: Jul 1995
- Country of Publication:
- United States
- Language:
- English
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