In-situ etching of InP by a low pressure transient HCI process

• Published in: Journal of crystal growth Vol. 73; no. 3; pp. 453 - 459
• Main Authors: Agnello, Paul D., Ghandhi, Sorab K.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 1985
• ISSN: 0022-0248; 1873-5002
• DOI: 10.1016/0022-0248(85)90008-9

Conditions are described for obtaining an in-situ etch for Inp subtrates, using hydrogen chloride gas. This is done by a transient process which avoids the need for maintaining an overpressure of phosphine during the etch step. It is shown that etching at low pressures can be carried out at an etching temperature which is compatible with the subsequent growth of lattice-matched GaInAs. The effect of varying the etching temperature, the HCI partial pressure, the total gas flow, and the substrate doping on the etch rate and morphology are also detailed. The etch process is shown to be to be kinetically controlled at reduced pressure and a polishing etch was achieved only at low etch rates. It is proposed that the desorption of InCl is the limiting step in this etch process.