Method of masking making semiconductor and etching beneath mask

Claim 1

A PROCESS FOR MANUFACTURING A SEMICONDUCTOR DEVICE, INCLUDING THE STEPS OF: PLACING AN APERTURED MASK ON A MAJOR SURFACE OF A SILICON SEMICONDUCTOR WAFER OF ONE CONDUCTIVITY TYPE, THE INTERFACE BETWEEN SAID MASK AND SAID MAJOR SURFACE BEING PENETRABLE BY A GASEOUS SILICON ETCHANT; EPITAXIALLY DEPOSITING SILICON OF OPPOSITE CONDUCTIVITY TYPE ON SAID MAJOR SURFACE THROUGH SAID APERTURE BY THE VAPOR PHASE REACTION OF HYDROGEN WITH A HALOGEN COMPOUND OF SILICON, SAID REACTION SIMULTANEOUSLY PRODUCING A VOLATILE HYDROGEN HALIDE CAPABLE OF ETCHING SILICON, WHEREBY DURING SAID DEPOSITION STEP SAID HYDROGEN HALIDE PENETRATES SAID INTERFACE TO ETCH THE PORTION OF SAID MAJOR SURFACE BENEATH SAID MASK; AND REMOVING SAID MASK FROM SAID SURFACE.