JPS55101853A - Method of fabricating comparison electrode with fet - Google Patents

Abstract

PURPOSE: To obtain a comparison electrode for a sensor which has excellent waterproofness and durability together with preferable performance by forming a special hydrophobic high molecular film on a gate insulating film of a gate insulated FET using a plasma generator of special construction.

CONSTITUTION: A plasma generator having a constrution that an electrode for applying high frequency is isolated from discharge atmosphere via an insulator is used. In an after-blow type, for example, external electrodes 12, 13 are connected from a bell-jar through an inductance matching circuit 14 to a power supply. Inert gas such as Ar or the like is introduced from a bomb 4 to the bell-jar 1, and reaction gas such as Teflon or the like is introduced from a bomb 6 through a conduit 5 to be injected from small holes perforated at a ring-like tube 15 in the bell-jar 1. A vacuum pump 10 is operated to evacuate the bell-jar 1 from the holes 8 of intake tube 7 formed with a specimen base 11 at the upper end in the bell-jar 1. The bell-jar 1 is evacuated to vacuum, Ar gas is introduced to the bell-jar 1, plasma produced through the electrodes 12, 13 is introduced from a nozzle 16 into the bell- jar 1, reaction gas is injected toward the plasma, the portion except for the gate of the FET is coated with a mask on the base 11, and a high molecular film containing more than 30% of F content is formed therein at a thickness of 300 to 10,000Å.

COPYRIGHT: (C)1980,JPO&Japio