Planar silicon field-effect transistors with Langmuir-Blodgett gate insulators

Abstract

The use of a planar fabrication process in the semiconductor industry has been the single most important factor in the phenomenal growth of the complexity level of integrated circuits (ICs). We report herein the first insulated-gate field-effect transistors (IGFETs) with Langmuir-Blodgett (LB) gate insulators to be fabricated on silicon in a manner which utilizes standard planar IC technology. This allows the manufacture of many (in this case 11) IGFETs and associated test structures on a single chip with a large number of chips per wafer. These devices are aluminum-gate enhancement-mode n-channel transistors with phosphorus-diffused sources and drains on a boron-doped (100) p-type silicon substrate. Preliminary results indicate a breakdown voltage of about 6 V for a ten-layer polymerized 10,12-nonacosadiynoic acid (16-8 diacetylene) gate insulator. The electrical parameters of these devices are comparable with that of the conventional IGFETs using SiO 2 as the gate insulator. Potential applications of these LB-film IGFETs include ultrathin gate devices for very-large-scale integration and chemical microsensors.