| 摘要 |
PURPOSE: To form a MOSFET which has an effective channel length larger than 1μm specifying first and second channel regions of the MOSFET, carrier density in the first and second channel regions, dielectric constant of gate oxide layer, and the effective channel length. CONSTITUTION: A first channel region reaches a depth such that it is smaller than about 500Åor is represented by tsi equivalent thereto. A second channel region reaches a depth such that it is almost tj smaller than tsi or is 1,000Åequivalent thereto. The carrier concentrations in the first and second channel regions are smaller than about 2×10<17> cm<-3> and larger than about 5×10<17> cm<-3> , respectively. A gate oxide layer has a dielectric constantεox , the first channel region has a dielectric constantεsi and an effective channel length Leff , a MOSFET has a scale lengthλdefined by a formula, and a thickness tox , tsi is selected such that the scale lengthλis smaller than or equivalent to 0.2Leff . The first channel region has an effective channel length that is equivalent to or smaller than 0.15μm.
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