Semiconductor device with input protection device

Abstract

Abstract PURPOSE:To make its oun area small and imput pretective device destruction-proof by using FAMOS type non-volatile semiconductor to a protective circuit. CONSTITUTION:A gate oxization film 5 is formed on the surface of n tupe S; plate 1 and n<+> highly thick layer 4 is formed in a channel on which a gate 6 is established and P type source area 2 and a drain area 3 are formed with a result of FAMOS type non-volatile memory Q 4. This drain electrode is connected to an input terminal through a resistor R1 and the joint V4 between the drain and the resistor R1 is connected to the input transistor Tr Q5 gate. Hight voltage added to the drain causes an avalanche between areas 2 and 4 and produces electrons which are trapped in a gate 6 and maintained. Thereby with the input protective TrQ4 beyond the specified voltage Q4 turns on and electrons are trapped again and on resistance of on-resistance of Q4 becomes smaller quickly. Therefore, TrQ5 is protected.

Inventors

• 👤 Takeshi Watanabe

Bibliographic Details