High- k gate dielectric GaAs MOS device with LaON as interlayer and NH 3 -plasma surface pretreatment
2015; IOP Publishing; Volume: 24; Issue: 12 Linguagem: Inglês
10.1088/1674-1056/24/12/127304
ISSN2058-3834
AutoresChao-Wen Liu, Jingping Xu, Lu Liu, Han‐Han Lu,
Tópico(s)Advancements in Semiconductor Devices and Circuit Design
ResumoHigh-k gate dielectric HfTiON GaAs metal-oxide–semiconductor (MOS) capacitors with LaON as interfacial passivation layer (IPL) and NH3- or N2-plasma surface pretreatment are fabricated, and their interfacial and electrical properties are investigated and compared with their counterparts that have neither LaON IPL nor surface treatment. It is found that good interface quality and excellent electrical properties can be achieved for a NH3-plasma pretreated GaAs MOS device with a stacked gate dielectric of HfTiON/LaON. These improvements should be ascribed to the fact that the NH3-plasma can provide H atoms and NH radicals that can effectively remove defective Ga/As oxides. In addition, LaON IPL can further block oxygen atoms from being in-diffused, and Ga and As atoms from being out-diffused from the substrate to the high-k dielectric. This greatly suppresses the formation of Ga/As native oxides and gives rise to an excellent high-k/GaAs interface.
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