METHOD FOR THE SELF-ALIGNMENT OF METAL CONTACTS ON A SEMICONDUCTOR DEVICE, AND SELF-ALIGNED SEMICONDUCTORS

摘要

Disclosed is a method for making self-aligned metal contacts on semiconductor devices, with a submicronic spacing between regions controlled by the contacts. On a semiconductor body supporting at least one raised pattern, a double layer of SiO2 and Si3N4 is deposited by an isotropic method. A double ionic etching of Si3N4 by SF6 and of SiO2 by CHF3 is done to insulate the sidewalls on the flanks of the pattern. A sub-etching by HF/NH4F/H2O creates a cap beneath each sidewall. The metal contacts, deposited by evaporation, are self-aligned and separated by a space "d" equal to the thickness of the insulating layers.