| 摘要 |
PURPOSE:To restrain any thermal strain of a nitride film while preventing the characteristics from time-elapsing detrioration by a method wherein a polycrystalline semiconductor layer is formed on the nitiride film by heat treatment. CONSTITUTION:Element isolating regions 11, 11 are formed on a P type silicon substrate 10 to make the space between regions 11, 11 an element forming region while impurity regions 12, 13 are formed respectively to be a source region or a drain region. The space between the regions 12 and 13 is made a channel forming region 14 while a selective gates 4, 5 formed into MNOS through the intermediary of a thin oxide film 3 are lined up with a memory gate 1 with a nitride film 2 as a gate insulating film. In such a constitution, the gate 1 is arranged on a position held by the gates 4, 5 in the section of element while a polycrystalline semiconductor layer containing impurity as the material of gate 1 is formed by heat treatment not exceeding 900 deg.C.
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