Amorphous silicon thin-film transistors with 90° vertical nanoscale channel

This letter reports 100nm channel length vertical thin-film transistors (VTFTs) in hydrogenated amorphous silicon (a-Si:H) technology. The channel length is defined by means of a dielectric film thickness, realized by an anisotropic reactive ion etching process to yield a 90° vertical transistor structure. Furthermore, the device area of the vertical TFT structure is less than ∼1∕3 that of the ubiquitous lateral TFT structure. The 100nm channel length VTFTs exhibit an ON/OFF current ratio of 108, a threshold voltage of 2.8V, and a subthreshold slope of 0.8V∕dec.

[1]  W. Anderson,et al.  Thin film transistors on nanocrystalline silicon directly deposited by a microwave plasma CVD , 2004 .

[2]  S. Wagner,et al.  Hole and electron field-effect mobilities in nanocrystalline silicon deposited at 150°C , 2002 .

[3]  M. Kimura,et al.  Low-temperature polysilicon thin-film transistor driving with integrated driver for high-resolution light emitting polymer display , 1999 .

[4]  Young Jin Choi,et al.  Electric-field-enhanced crystallization of amorphous silicon , 1998, Nature.

[5]  M. Matsumura,et al.  Excimer-Laser-Produced Amorphous-Silicon Vertical Thin-Film Transistors , 1997 .

[6]  M. Matsumura,et al.  Short-channel amorphous-silicon thin-film transistors , 1996 .

[7]  R. Street,et al.  Hydrogenated amorphous silicon: Index , 1991 .

[8]  G. Fortunato,et al.  Source-Drain Metal Contact Effects in Short-Channel a-Si:H Thin-Film Transistors , 1990 .

[9]  J. Shaw,et al.  Vertical amorphous silicon thin‐film transistors , 1990 .

[10]  M. Matsumura,et al.  Short-channel a-Si thin-film MOS transistors , 1989 .

[11]  Arun Madan,et al.  The Physics and Applications of Amorphous Semiconductors , 1988 .

[12]  G. Oehrlein,et al.  Silicon etching mechanisms in a CF4/H2 glow discharge , 1987 .

[13]  Y. Uchida,et al.  Vertical-Type Amorphous-Silicon Field-Effect Transistors with Small Parasitic Elements , 1986 .

[14]  Y. Nara,et al.  Proposed vertical-type amorphous-silicon field-effect transistors , 1984, IEEE Electron Device Letters.

[15]  Vincent M. Donnelly,et al.  Basic chemistry and mechanisms of plasma etching , 1983 .

[16]  H. F. Winters,et al.  Plasma etching—A discussion of mechanisms , 1979 .