Bonding Structure at the SiO and In2O/III-V Semiconductor Interface

摘要: The Si based MOS field effect transistors (MOSFETs) technology is rapidly approaching its theoretical physical limits . III-V compound semiconductors are known as a potential additional platform to silicon key fabricating practical MOSFET forming an unpinned oxide-semiconductor interface with low fixed charge, and trap density. Determining atomic bonding structures critical understanding passivation. Atomically resolved scanning tunneling microscopy (STM) was been combined density function theory (DFT) determine the structure of gate-oxide/IIIV interfaces. In-rich InAs(001)-(4×2) can readily be prepared by decapping As2 capped InAs(001) wafers. STM results reveal that has very different than Ga-rich GaAs(001)-ζ(4×2) even though surfaces have similar symmetry. denoted β3(4×2) unit cell consisting two undimerized group III atoms on row dimers in trough showed initial deposited In2O molecules bond edges rows most likely form new In-As bonds surface without any disruption clean structure, shown Fig. 1. Annealing In2O/InAs(001)-(4×2) 380 C formation flat ordered monolayer rectangular islands, 2a. DFT simulations show annealed no longer just As at edge but also forms O-In trough, 2b. SiO InAs(001)-(4×2). At room temperature, chemisorption InAs-(4×2) completely Fig 3a. themselves nanoclusters. configuration nearly identical when SiO/InAs sample (Fig. 3b). Both depositions do not displace during both temperature deposition post-deposition annealing. calculations confirmed experimental findings. For In2O, In2O-In sites more stable In-O-In-As about ~0.77 eV/In2O. SiO, there four degenerated structures. Literature for pure substances (not InAs chemisorbates) higher sublimation energy (∆H: 3.3 eV vs. 2.6 eV), see 4. It hypothesized lower selfbonding allows island, while self-bonding induces multilayer disorder amorphous