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High mobility Ⅲ-Ⅴ semiconductors have attracted great attention for future high performance metal-oxide-semiconductor field-effect transistors,considered as candidates to replace strained-Si.[1]Many high performance Ⅲ-Ⅴ channel MOSFETs have been reported.[2]GaSb has very high hole mobility (~1000 cm2/V·s),making it attractive as an alternative channel material to silicon,especially for the p-channel MOSFETs application.[3,4]The hole mobility of GaSb is one of the highest mobilities among the Ⅲ-Ⅴ semiconductors and twice as high as silicon and GaAs.[5]Strain engineering is considered as one of the most promising technologies to improve the mobility of Ⅲ-Ⅴ MOSFETs because techniques that enhance the mobility are urgently demanded to realize the full potential of Ⅲ-Ⅴ MOSFETs.[6]Physical understanding of the strain effect on the MOSFETs is also of great importance.In this work,GaSb p-channel MOSFETs with Al2O3 gate dielectric and source and drain formed by ion implantation that are self-aligned with respect to the gate are experimentally demonstrated,and various biaxial compressive strains were introduced by depositing a Si3N4 cap layer.The mobility of the strained GaSb MOSFETs is 3.86 times as high as that of the control samples without a strain.Meanwhile,first principles calculations show that hole effective masses of GaSb depend on a biaxial compressive strain.The biaxial compressive strain brings a remarkable enhancement of the hole mobility caused by significant reduction of the hole effective masses due to the modulation of valence bands.