第65回ナノ・スピン工学研究会

2013.03.04

研究会名：第65回ナノ・スピン工学研究会

開催日：2013年3月4日（月）11:00～12:00

開催場所：東北大学電気通信研究所ナノ・スピン実験施設4階A401

講演者：Prof. James C. Sturm (Princeton University)

講演題目：“Wide Bandgap Heterojunctions on Crystalline Silicon”

第65回ナノ・スピン工学研究会開催のご案内

東北大学　電気通信研究所
ナノ・スピン実験施設
ナノ集積デバイスプロセス研究部
佐藤　茂雄

ナノ・スピン工学研究会の講演会を下記のとおり開催いたします。多数御来聴下さいますようご案内申し上げます。

日時：2013年3月4日（月）11:00～12:00
場所：東北大学電気通信研究所ﾅﾉ･ｽﾋﾟﾝ実験施設4階A401
講演者：Prof. James C. Sturm (Princeton University)
講演題目：“Wide Bandgap Heterojunctions on Crystalline Silicon”

[ Abstract ]

For 30 years there has been extensive research on pseudomorphic strained Si_1-xGe_x semiconducting layers grown on the (100) surface of crystalline silicon. This technology provides a narrow bandgap compared to silicon, and has long been established in industrial production to make heterojunction bipolar transistors. On the other hand, despite the great wishes of the designers of silicon-based devices, there has been little progress to date on wide-bandgap heterojunctions on silicon. In this talk we present the development of both electron-blocking (large conduction band offset, small valence band offset) and hole-blocking (large valence band offset, small conduction band offset) heterojunctions on silicon.

Our work is based on organic semiconductors and inorganic metal oxide semiconductors, which can have bandgaps of 3-5 eV. Thus very large blocking barriers are possible, and are confirmed by electronic structure measurements of the widegap/silicon interface. The material phases we use are amorphous, and hence the lattice-mismatch problem is avoided. However, great care must be taken to passivate the surface silicon atoms to reduce interface defects, in some cases using “hybrid” semiconducting molecules as a structural and electronic “bridge” between the different semiconductor systems. Finally, we demonstrate the application of these widebandgap heterojunctions on silicon in photovoltaic devices, MISFET’s, and in heterojunction bipolar transistors.