| 摘要 |
PURPOSE:To make it possible to increase a drain current without reducing an operation speed by forming a semiconductor region of the same conduction type as a gate region under a drain region and next to the gate region. CONSTITUTION:At the boundary part between channel region 10 under drain region 20 and high-density semiconductor substrate 1, P-type region 50 is formed. Since gate region 30 is formed surrounding drain region 20, region 50 is close to gate region 30. As a result, a current flows right under gate region 30. In an OFF mode, equalizing gate electrode 300 to source electrode 100 in terms of voltage cuts off a drain current through expansion D1 of a depletion layer from region 30 to region 10 and expansion D2 of a depletion layer from region 50 to region 10, and consequently both W and L of region 10 can be elongated, so that this area can freely be widened corresponding to the drain current. |
