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High Resistivity GaAS by Vapor Growth

IP.com Disclosure Number: IPCOM000096238D
Original Publication Date: 1963-Feb-01
Included in the Prior Art Database: 2005-Mar-07
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Hull, EM: AUTHOR [+2]

Abstract

In making runs to deposit N or P-type GaAs on GaAs substrates, it has been the general practice to use single crystal GaAs pulled from melts contained in silica crucibles as the source feed material. This source GaAs usually contains about 1 x 10/17//cc of silicon as an impurity. The vapor grown GaAs crystals obtained using the typical source have carrier concentrations varying between 5 x 10/15//cc to 5 x 10/16//cc in both N and P-type material.

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High Resistivity GaAS by Vapor Growth

In making runs to deposit N or P-type GaAs on GaAs substrates, it has been the general practice to use single crystal GaAs pulled from melts contained in silica crucibles as the source feed material. This source GaAs usually contains about 1 x 10/17//cc of silicon as an impurity. The vapor grown GaAs crystals obtained using the typical source have carrier concentrations varying between 5 x 10/15//cc to 5 x 10/16//cc in both N and P-type material.

In this method, when source GaAs containing silicon to a level of 6 x 10/17//cc is employed, the resulting vapor grown crystals are Ptype with room temperature resistivities of 10/4/ to 10/5/cm. Thus, the resistivity of the vapor grown GaAs increases by a factor of 105 to 106 by changing the doping concentration of the source material by only three to six times. The high resistivity GaAs produced by this method also exhibits relatively high hole mobilities, the average being around 300 cm/2//v-sec. while the highest was 460 cm/2//v-sec. This indicates that the material is reasonably pure. Conventional methods to produce high resistivity GaAs employ doping with two opposite conductivity type elements to high levels, thus obtaining the high resistivity through charge compensation.

In the mechanisms involved in this process, it is thought that silicon is being incorporated in the GaAs on defect sites which are controlled through the arsenic pressure. The silicon is compensating the char...