Investigations of beryllium in CBE grown epitaxial layers and profiling of multilayers by electro-chemical C– V measurements

Abstract

Profiling of p-type dopant in low band gap materials such as indium gallium arsenide (InGaAs) and indium phosphide (InP) were carried out using a computer controlled electro-chemical carrier profiling system. The electrically active carrier concentration of beryllium (Be), a widely used p-type dopant, has been investigated in the chemical beam epitaxially (CBE) grown InP and InGaAs layers. At very high Be doping, the surface roughness and the formation of Be precipitates on the growing InP or ternary surface seems to influence the electro-chemical capacitance–voltage (ECV) profiling of Be dopant. The profiling of heavy Be dopant is limited by the surface degradation of the epilayers. The ECV measurements combined with the stylus profiler measurements further show the abruptness of the growth interface and it confirms the interface control of the grown epi-materials. We also show the complete profiling of a multilayer structure grown by the CBE technique for opto-electronic and photonic applications.