Semiconductor gas sensor and method for producing the same

摘要

A technique capable of realizing a semiconductor gas sensor having a high rising response speed is provided. A gate insulating film (e.g., a SiO2 film) is formed on a Si layer, and a modified TiOx (a TiOx nanocrystal) film is formed on the gate insulating film. Further, on the modified TiOx film, a Pt film is formed. This Pt film is composed of a plurality of Pt crystal grains, and in a crystal grain boundary gap existing among the plurality of Pt crystal grains, Ti and oxygen (O) are present, and particularly, a TiOx nanocrystal is formed on a surface in the vicinity of a grain boundary triple point as the center.

主权项

1. A semiconductor gas sensor, comprising:
(a) a semiconductor layer; (b) a gate insulating film formed on the semiconductor layer; (c) a crystalline film formed on the gate insulating film; (d) a gate electrode formed on the crystalline film; (e) a source region formed on the semiconductor layer; (f) a drain region formed on the semiconductor layer; and (g) a plurality of grain boundary regions, wherein
the crystalline film is composed of modified TiOx, the modified TiOx being formed from a TiOx microcrystalline region and an oxygen-doped amorphous Ti region, and the ratio of the TiOx microcrystalline region is 50% or more,the gate electrode has a platinum film or an iridium film, the platinum film or the iridium film is composed of a plurality of crystal grains, andat least one grain boundary region includes oxygen and titanium and is disposed between immediately adjacent crystal grains, the at least one grain boundary region preventing the formation of a gap between the immediately adjacent crystal grains.