Self-aligned contacts in an ion implanted VLSI circuit

摘要

A process for producing VLSI (very large scale integrated) circuits employs techniques of self-aligned gates and contacts for FET devices and for both diffused conducting lines in the substrate and polysilicon conducting lines situated on isolating field oxide formed on the substrate. Mask alignment tolerances are increased and rendered non-critical. The use of materials in successive layers having different etch characteristics permits selective oxidation of only desired portions of the structure without need for masking and removal of selected material from desired locations by batch removal processes again without use of masking. There results VLSI circuits having increased density and reliability. The process allows the simultaneous doping of two or more regions resulting in uniformity of device characteristics.