Twin generation in zinc-blende type III-V compound semiconductors: new insights from an InP case study

The type of twinning in zincblendeor sphalerite-type III-V compound semiconductors is well known. However, its detailed formation mechanism, although intensively studied in the eighties and nineties, is not entirely understood. In addition to a lot of empirical observations, there is a theoretical approach, published in 1995 [1] and improved in 1998 [2]. The latter predicts a correlation between crystal slope angle a and twin generation frequency. However, a critical overview of our own experimental results on GaAs and InP, grown by LEC (Liquid Encapsulated Czochralski) and VCz (Vapour Pressure controlled Czochralski) techniques, leads to no unambiguous relation between twin formation and crystal slope angle. This paper gives a comparison between experimental results and the above mentioned theory, revealing that twinning is more correlated to dynamical effects like oscillations of growth rate, i.e. noise of the system.