HEAT INSULATING SINGLE PIECE SEMICONDUCTOR DIE AND METHOD OF PRODUCING SAME

摘要

A process for producing thermally isolated monolithic semiconductor die and die produced by the process, plus improved apparatus using the die are disclosed. The process generally comprises the steps of: forming a desired semiconductor component or circuit in a semiconductor wafer (preferably a silicon wafer of 100 crystal orientation) having a protective layer (SiO2) on one surface; forming platinum silicide contact windows in said protective layer where external connections to the semiconductor component or circuit is necessary; forming support leads of a layer of adhesive material (which also may have resistive properties, such as Nichrome) and a layer of a structurally strong metal of high electrical conductivity and low thermal conductivity (preferably 304 stainless steel) along predetermined paths extending outwardly toward the edge of the die from said contact windows; simultaneously with the forming of the adhesive layer of said support leads, forming one or more thin film resistors in predetermined regions of said die atop said SiO2 protective layer, if desired; removing said SiO2 protective layer from a region defined by said support leads, an island or islands in which said semiconductor component or circuit and said resistors are formed and a surrounding frame; and, removing said silicon from the region between said island or islands and said frame. The resulting semiconductor die comprises a frame surrounding one or more islands in which semiconductor components or circuits are formed, and which support resistors, if included. The islands are entirely supported by the support leads extending between the frame and the islands. In addition to providing support, the support leads also provide for electrical connection to the semiconductor components or circuits and to the resistors. The semiconductor die may be mounted in a package that also forms part of the invention. The package includes a ceramic substrate having an aperture in its center and alignment mesas and ridges on one surface. The ceramic substrate is formed so as to be mounted on the metal header of a conventional semiconductor canister housing. Depending upon their specific nature the resulting die are useful in and/or improve a variety of electrical apparatus. They are particularly useful as the dual RMS sensor element of an RMS converter. They can also be formed so as to be useful as radiation sensors. Or, they can be formed so as to provide a thermal platform whose temperature is controlled and stabilized at a predetermined value. All of these dies and the improved circuits resulting from their use also form part of the invention.