Humidity sensitive semiconductor element

Abstract

Abstract PURPOSE:To obtain a humidity sensitive element having a P-N joint which has a high sensitivity and a long life and also a high mass productivity, by protecting the joining part by an oxidation film and forming a metallic layer electrode and a film made of one kind or more of a specific resin on the oxidation film as a humidity sensitive protective film. CONSTITUTION:For example, a p type diffusion layer 2 is formed on an n type silicon substrate 4 and exposed portion of P-N joining of a PNP type MOS element provided with a source electrode 5, a gate electrode 6 and a drain electrode 7, is protected by an insulation film 1 such as SiO2, Si3N4. Next, a humidity sensitive protective film 3 is formed on the film 1 by using one kind or more of polyester, polyester sulfon, polyimide, polyimidoether sulfon, polyimido sulfon, polyimidoquinazoline-dione and silicone resin. Hereby, there is a relation of a straight line between the relative humidity of the humidity sensitive element and a logarithm of a leakage current and the current is increased in accordance with an elevation of the humidity. Thus, the element having a high sensitivity and a stain resistance for adsorption of dust, cigarette smoke or waste gas of a motorcar and also, a hydrolysis resistance and moreover, a long life, is obtained.

Inventors

• 👤 Takashi Yokoyama
• 👤 Tokuyuki Kaneshiro
• 👤 Hiroshi Suzuki

Bibliographic Details