MOSFETs with sub-0.1 µm gate length were fabricated, and their low temperature operation was investigated. The drain current for drain voltage of 2 V increased monotonously as temperature was lowered to 15 K without an influence of the freeze-out effect. Moreover, the increase in the drain current was enhanced by the gate length reduction. The hot-carrier effect at low temperature was also investigated. Impact-ionization decreased as temperature was lowered under the condition of drain voltage 2 V. The decreasing ratio was enhanced as gate length became shorter. We consider this phenomenon is attributed to the non-steady-stationary effect. As a result, device degradation by DC stressing was reduced at 77 K in comparison with room temperature. In the case of 0.1 µm MOSFET, drain current was not degraded in condition of DC stress with gate- and drain-voltage was 1.5 V.

It is clarified that the SiN$_{mathrm{X}}$ film with a thickness of 1.7 nm, which was formed at the interface between the poly-Si source/drain and Al layer, suppresses the hump phenomenon of TFT with a channel length of 10, $mu $m. The mechanism of the hump suppression by this structure is discussed. It is thought that the fixed charge in the SiN$_{mathrm{X}}$ film suppresses the formation of the parasitic channel in the poly-Si edge by the Coulomb repulsion.

Systems for removing particulates and gaseous contaminants using the UV/photoelectron method under atmospheric and low pressure conditions have been investigated and its availability has been demonstrated. From experimental results, more than 90 % of particulate contaminants are removed by this method under atomospheric and low pressure conditions. This method can be used to design superclean spaces for wafer stockers, and wafer delivering systems in the LSI fabrication process.