Energy distribution of interfacial trap density in high κ dielectrics/In0.2Ga0.8As MOS and its impact on MOSFETs performance

• Main Authors: Lai, Lai-Hung, 賴來宏
• Other Authors: Hong, Minghwei
• Format: Others
• Language: en_US
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/04003891323178785428

碩士 === 國立清華大學 === 材料科學工程學系 === 98 === III-V InGaAs metal-oxide-semiconductor field-effect-transistors (MOSFETs) with high-κ dielectrics are now a strong contender for tech-nologies beyond the 16 nm node complementary MOS (CMOS), due to the high electron mobility of InGaAs, 6-18 times than that of Si. Attain-ment of low interfacial trap densities (Dit) for the high-k dielec-trics/InGaAs MOS is critical for inversion-channel MOSFETs, so are the electrical measurements to characterize them. Quasi-static C-V (QS-CV) measurements were carried out on Al2O3/Ga2O3(Gd2O3)[GGO]/(n- and p-) In0.2Ga0.8As grown by molecular beam epitaxy (MBE) and Al2O3/(n- and p-)In0.2Ga0.8As grown by Atomic layer deposition (ALD), followed by the simulation to determine the Dit distribution. From the QS-CV measurements and simulations, the Dit dis-tribution within the band gap shows flat distribution in GGO/In0.2Ga0.8As, and Dit with a value of ~1012eV-1cm-2 was found. However, there is an obvious bump of Dit in the mid-gap of ALD Al2O3/In0.2Ga0.8As, and Dit is ~1013eV-1cm-2. After 850℃ RTA, midgap exhibits more interfacial traps, and Dit is ~5×1013eV-1cm-2. The electrical analysis proves that owing to efficacious passivation and higher thermal budget of InGaAs surface, MBE-GGO/InGaAs is the proper structure for MOSFETs.