| 摘要 |
PURPOSE:To operate a semiconductor device stably at high speed by bringing impurity concentration in a region, in which carriers travel, to 10<14> atoms/cm<3> or less. CONSTITUTION:Field silicon oxide films 5 and a gate silicon oxide film 3 are formed onto a p type silicon substrate 1 in boron concentration of approximately 1.5X10<13> atoms/cm<3>, and arsenic is implanted into a channel region to form an n type layer 6. Arsenic is added into source-drain regions 2 while using a gate electrode 4 as a mask. Accordingly, impurity concentration in a region in which carriers travel is brought to 10<14> atoms/cm<3> or less, and the mobility of carriers increases when an operating temperature is lowered. A semiconductor device can be operated stably at high speed because the substrate is brought to a semi-insulated state. |
