TABLE OF CONTENTS L. Haji (revised by A.R. Peaker)
June 1998
In bulk InP crystals, grown by the liquid encapsulation Czochralski (LEC) method, several kinds of defect have been detected and extensively investigated by various analytical techniques. Chemical etching [1] is a common tool to reveal some of these defects. However, due to its high resolving power and ability to provide detailed structural information, transmission electron microscopy (TEM) is especially suitable for the study of extended defects in InP.
The principal extended defects in InP are dislocation lines, inclusion-like defects, dislocation loops and twins. The special case of micro-precipitates is dealt with in detail in Datareview 6.2 in this book.
The grown-in defects include all crystalline defects which are generated during the growth of InP crystals. The two major kinds of defect usually detected in bulk InP are threading dislocation lines and defect clusters.
Dislocations are line defects induced by easy glide in the {111}<110> slip system as a result of stresses due to thermal gradients present during the growth process. The dislocation density in undoped LEC crystals is generally high and can reach 10 5 cm -2 [2]. This density can be reduced to below 10 3 cm -2 for undoped large diameter crystals grown by the dynamic gradient freeze (DGF) technique [3].
It is well known, in crystal growth, that the incorporation of suitable impurities at concentrations higher than 10 18 atoms/cm 3
