Tokyo Institute of Technology · 공학
Kuniyuki Kakushima 교수의 연구실은 전자재료 및 반도체 소자의 핵심 소재인 산화물 및 nitride 계 고성능 페로일렉트릭 재료의 박막 성장과 물성 특성 분석을 중심으로 연구를 진행하고 있습니다. 특히 스퍼터링법을 활용한 알루미늄-scandium nitride(AlScN) 페로일렉트릭 박막의 실온 성장과 고온 처리에 의한 물성 향상, 고주기 내구성 메모리 소자 응용 가능성을 탐색하고 있으며, 고k 절연막과 반도체 인터페이스의 표면 전자구조 및 밴드 번딩 분석을 위한 하드X선광전자분광법(HAXPES) 기반의 정밀 분석 기술도 개발하고 있습니다. 이와 더불어 3D 스케일링 기반의 고전력 IGBT 소자 기술 개발을 통해 전력 반도체의 효율성 향상에도 기여하고 있습니다.
표시된 성과는 수집된 데이터 기준으로 산출되며, 일부 차이가 있을 수 있습니다.
Crystallographic characterization and the ferroelectric properties of 50 nm-thick sputter-deposited Al0.78Sc0.22N films deposited at room temperature (RT) and 400 °C are investigated. c-axis oriented growths were confirmed by x-ray diffraction patterns with rocking curve measurements for both samples. Al0.78Sc0.22N films were found to grow in the c-axis direction and showed poling-free ferroelectric properties, which are advantageous for practical memory and piezoelectric applications. Although
Band bendings of Si substrates have been observed using hard x-ray photoemission spectroscopy. With a capability of collecting photoelectrons generated as deep as 40 nm, the binding energy shift in a core level caused by the potential profile at the surface of the substrate results in a spectrum broadening. The broadening is found to be significant when heavily doped substrates are used owing to its steep potential profile. The surface potential of the substrate can be obtained by deconvolution
Three dimensionally (3D) scaled IGBTs that have a scaling factor of 3 (k=3) with respect to current commercial products (k=1) were fabricated for the first time. The scaling was applied to the lateral and vertical dimensions as well as the gate voltage. A significant decrease in ON resistance, - Vce(sat) reduction from 1.70 to 1.26 V - was experimentally confirmed for the 3D scaled IGBTs.
Oxygen bonding in La-silicate film with compositional gradient has been characterized by x-ray photoelectron spectroscopy. Based on an analytical model of bridging and nonbridging oxygen, the O 1s spectra arising from La-silicate layer have been deconvoluted with compositionally dependent parameters. For a composition ratio of 1:1 for SiO2 and LaO1.5 on the surface of the La-silicate layer, negative binding energy shifts of 0.35 and 0.10 eV for bridging and nonbridging oxygen, respectively, have
