Abstract:
THE NVENTION IS A METHOD OF FABRICATING SEMICONDUCTOR DEVICES WHICH HAVE THE UNIFORM AVALANCHE BREAKDOWN JUNCTIONS CHARACTERISTIC OF PRIOR ART MESA DEVICE STRUCTURES WHILE RETAINING THE DESIRABLE PASSIVATION AND OVERLAY CONTACT FEATURES CHARACTERISTIC OF PLANAR STRUCTURES. AN IMPORTANT FEATURE IS BASED ON THE FACT THAT THE BULK INCREASES WHEN SILICON IS CONVERTED TO THE OXIDE WHEREBY DEPRESSIONS IN A SILICON BODY CAN BE FILLED BY SELECTIVE OXIDATION OF THE REGIONS OF THE DEPRESSIONS.
Abstract:
This method of fabricating junction-isolated semiconductor integrated circuit devices eliminates the photolithographic masking operation associated with a base diffusion by performing a non-selective P-type base diffusion into the entire surface of a thin N-type epitaxial layer. The lateral extent of base zones and resistor zones is defined by selectively diffusing low resistivity N-type deep contact zones completely through the epitaxial layer to intersect the entire perimeter of a buried Nlayer. Junction isolation, consisting of either back-to-back diodes or junction field-effect transistors, may be used.
Abstract:
IN THE FABRICATION OF A JUNCTION-ISOLATED SEMICONDUCTOR INTERGRATED CIRCUIT STRUCTURE, A PLURALITY OF N-TYPE BURIED LAYERS ARE DIFFUSED INTO A P-TYPE SUBSTRATE, AND A THIN PTYPE EPITAXIAL LAYER IS GROWN THEREOVER. N-TYPE DEEP CONTACT ZONES ARE DIFFUSED COMPLETELY THROUGH THE EPITAXIAL LAYER TO INTERSECT SEPARATE ONES OF THE N-TYPE BURIED LAYERS, THUS DEFINING BASE AREAS. P-TYPE IMPURITIES ARE THEN DIFFUSED NON-SELECTIVELY INTO THE ENTIRE SURFACE OF THE PTYPE EPITAXIAL LAYER TO FORM A GRADED IMPURITY PROFILE FOR THE BASE ZONE. N-TYPE EMITTER ZONES ARE THEN DIFFUSED SELECTIVELY INTO THE SURFACE.