| 摘要 |
PURPOSE:To increase the density of a dynamic RAM by using as a substrate N/P or N/P/N epitaxial substrate, forming a channel in the same conductivity type buried channel structure as source, drain, and forming the channel in a completely depleted state in a main operating range. CONSTITUTION:An N-type layer 102 is grown on a P-type Si substrate 101, a P<+> type channel stopper region 114 is formed on the periphery, and a thick field oxide film 107 is coated thereon to insularly form the layer 102. An N<+> type source region 103 and drain region 104 are diffused in the surface layer of the insular layer 102, and a gate electrode 106 to become a word line is formed through a gate oxide film 105 therebetween. A source electrode 109 to become a bit line is formed on the region 103, and a plate electrode 110 and an electrode 112 through an insulating film 111 are formed on the region 104 as a dynamic RAM. Thus, the channel can be formed in a completely depleted state to avoid the software error due to alpha-particles, the decrease in VT due to a punch-through. |
