Preparation and Properties of Epitaxial Gallium Phosphide

Abstract

Gallium phosphide has been grown epitaxially by open tube vapor transport using Ga and PCI3 as starting materials. The over-all reaction for the process can be represented by 5Ga ~-2PC13 ~ 2GaP + 3GaC12. The undoped GaP obtained is p-type with carrier concentration ,-,1014 cm -3 and mobilities up to 150 cm 2 v -1 sec -1 at 300~ The transport properties as well as the mass spectroscopic analysis are presented and demonstrate the high purity of the GaP. The addition of water vapor to the hydrogen carrier gas progressively raises the resistivity of the p-type epitaxial layer. Semi-insulating GaP has been produced by this method with resistivities over 10 TM ohm cm.

Study of Localized Levels in Semi-Insulators by Combined Measurements of Thermally Activated Ohmic and Space-Charge-Limited Conduction

“…11 The addition of water vapor to the H 2 carrier gas progressively raises the resistivity of these crystals, and it has been conjectured that O, acting as a compensating n-type impurity, would be responsible for this behavior. Figure 5 shows a set of current-voltage curves at several different temperatures for single-crystal ^-type GaP.…”

The electrical properties of undoped and oxygendoped GaP grown by the liquid encapsulation technique

“…Most of these have been on doped material (Montgomery 1968, Taylor et al 1968, Casey et al 1969 but there have been some on undoped material (Epstein 1966, Kamath and Bowman 1967, Miyauche et al 1967 although none on liquid encapsulated material. The electrical impurity in most undoped material appears to be either S or Si, although in undoped vapourgrown material an unidentified acceptor level at 0.35 eV has also been detected (Kamath and Bowman 1967). The highest mobilities reported in n type material are 187 and 2000 cm2 V-1 s-1 at room and liquid-nitrogen temperatures respectively.…”

An Analysis for Si Contamination in GaP

“…The procedure as presented was derived from crystal growth experiments and relies on an unintentional moisture content of the reactants. The experimenter can control the moisture content of the reactant gas by saturating part of the incoming hydrogen with water vapor by passing it through a temperature controlled water bubbler as .described by Kamath and Bowman (14).…”