Doping level selective photochemical dry etching of GaAs

Journal Article · Mon Apr 15 04:00:00 EST 1985 · Appl. Phys. Lett.; (United States)

DOI:https://doi.org/10.1063/1.95496· OSTI ID:5815172

Ashby, C I.H.

The first observation of a highly selective photochemical dry etching process which discriminates between semiconductor materials differing in dopant concentrations by less than a factor of 5 is reported here. A photochemical reaction of GaAs with gas phase reactive Cl species occurs when the surface is irradiated with low-intensity light of band gap or greater quantum energies. Application of an appropriate negative bias to a GaAs sample can almost totally suppress the photochemical reaction of heavily doped n-GaAs, while less heavily doped n-GaAs or p-GaAs continue to etch at undiminished rates under the same conditions. This is the first reported etching process to produce greater than 20:1 selectivity for doping levels differing by less than a factor of 5. A mechanism which may explain the origin of the photochemical reaction and the voltage-controlled doping level selectivity which it displays is presented here. The potential significance of these observations for other semiconductor materials, such as Si, is discussed.

• Research Organization: Sandia National Laboratories, Albuquerque, New Mexico 87185
• OSTI ID: 5815172
• Journal Information: Appl. Phys. Lett.; (United States), Journal Name: Appl. Phys. Lett.; (United States) Vol. 46:8; ISSN APPLA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360103* -- Metals & Alloys-- Mechanical Properties
ARSENIC COMPOUNDS
ARSENIDES
CHEMICAL REACTIONS
CHEMISTRY
CHLORINE
CRYSTAL DOPING
ELEMENTS
ETCHING
GALLIUM ARSENIDES
GALLIUM COMPOUNDS
HALOGENS
NONMETALS
OXIDATION
PHOTOCHEMICAL REACTIONS
PHOTOCHEMISTRY
PNICTIDES
SEMIMETALS
SILICON
SURFACE FINISHING