Browse Prior Art Database

In-situ Plasma Sulfide Treatment

IP.com Disclosure Number: IPCOM000121226D
Original Publication Date: 1991-Aug-01
Included in the Prior Art Database: 2005-Apr-03
Document File: 1 page(s) / 32K

Publishing Venue

IBM

Related People

Callegari, A: AUTHOR [+5]

Abstract

Disclosed is a plasma sulfide treatment applied on GaAs surfaces which reduces surface state densities as well as surface recombination velocities. When aqueous solutions containing sulfur are spun on GaAs wafers, native oxides and elemental As are etched away exposing a pristine surface to which sulfur can bond [1]. This process has shown dramatic improvement in laser performance and in GaAs/AlGaAs heterostructure bipolar transistor [1].

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 100% of the total text.

In-situ Plasma Sulfide Treatment

      Disclosed is a plasma sulfide treatment applied on GaAs
surfaces which reduces surface state densities as well as surface
recombination velocities.  When aqueous solutions containing sulfur
are spun on GaAs wafers, native oxides and elemental As are etched
away exposing a pristine surface to which sulfur can bond [1].  This
process has shown dramatic improvement in laser performance and in
GaAs/AlGaAs heterostructure bipolar transistor [1].

      In this article, an in situ plasma process is proposed. GaAs
surface sulfurization is achieved by exposing the surface to an RF
plasma done at low pressure, low power, for a very short time in a
SF6/H2 gas mixture.  This process has been shown to leave a thin
sulfur layer on Si/Ge surfaces (2).  This plasma process can be used
for laser passivation, MESFET passivation [3], GaAs, InGaAs, and InP
MOSFETs.

      References
(1)  C. J. Sandroff, R. N. Nottenburg, J. C. Bischoff and R. Bhat,
"Dramatic enhancement in the gain of a GaAs/A1GaAs heterostructure
bipolar transistor by surface chemical passivation," Appl .  Phys .
Lett . 51, 33 (1987).
(2)  G. S. Oehrlein and T. D. Bestwick, P. L. Jones, and J. W.
Corbett, "Selective dry etching of silicon with respect to
germanium," Appl . Phys . Lett . 56, 1436 (1990).
(3)  "Oxide-Free Dielectric/GaAs Interface with No Excess As," IBM
Technical Disclosure Bulletin 33, 352 (April 1991).