Epitaxial growth and processing of high-aspect ratio InGaAs fins for advanced MOSFETs

Sammanfattning: In this thesis, InGaAs fins with vertical sidewalls consisting of {110} facets were epitaxially grown on InP(111)B substrates using metalorganic vapor phase epitaxy. A lithography patterned hydrogen silsesquixane growth mask was used to promote the formation of vertical {110} facets during the growth. The relative growth rate of the {111B} and {110} facets was controlled by the input V/III ratio in the gas phase. It was found that for low V/III ratios, high InGaAs fins with minimal mask overgrowth could be grown. Facet selective growth of InGaAs fins on InP(111)B can thus be used to fabricate the channel in modern fin field-effect transistors (FinFETs). Prior to the growth of InGaAs fins, the chemical composition of epitaxially grown InGaAs films on different InP substrates was measured using reciprocal space mapping. The purpose of this was to calibrate the InGaAs growth in terms of chemical composition on various crystal facets. Several thin InGaAs films were grown at 600 C using trimethyl gallium, trimethyl indium, and arsine. The results revealed that the chemical composition of InGaAs on InP(111)B, InP(110), and InP(001) differed considerably when grown during identical conditions. It was found that thin InGaAs films of good crystal quality could be grown on InP(111)B and InP(001) during these conditions. The growth on InP(110) during the same conditions resulted in relaxed gallium rich InGaAs films.