CS240040B1 - Method of power diode structure production - Google Patents

Abstract

The solution is to reduce production cost that is achieved by silicon board with cut surface from single-silicon single crystal etching, further diffusion of aluminum from of the diffuser layer applied to the non-etched side of silicon wafer at 1250 * 20 ° C for a maximum of 25 hours bilateral diffusion of phosphorus at temperature 1200 to 125 ° C for a maximum of 3 hours. Then the silicon wafer is bonded on the side extruded with molybdenum dilatation aluminum electrode using aluminum foil or aluminum-silicon based film thicknesses 40 to 70 nm at 65 ° to 800 ° C vacuum or protective atmosphere.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention

In power semiconductor diode technology, a mono * crystalline silicon wafer is used as a starting material for high temperature operations, which, after cutting from the crystal, is abraded / flapped to a definite thickness. but the PN transitions formed into this surface are inhomogeneous · diffusion of aluminum into the brushed surface is usually followed by diffusion of boron and phosphorus, each layer being formed to a different side of the plate, which requires masking or respeleption operations precision operations and high capacity operations of technological equipment, such as: plate grinding, oxidation, photoresist coating, boron diffusion and the like.

Disadvantages of high costs are solved by the method of production of the power diode structure according to the invention, which consists in that the silicon wafer, with the surface treated by cutting from single silicon crystal, is etched unilaterally, further aluminum diffuses from the diffusant layer 1250 and 20 ° C for a maximum of 25 hours · followed by bilateral phosphorus diffusion at a temperature of 1200 to 1250 ° C for a maximum of 3 hours · after which the silicon wafer is soldered to

The aluminum-silicon-based aluminum-silicon-based foil has a thickness of 40-70 ° at a temperature of 650-800 ° C under vacuum or a protective atmosphere.

The method of manufacturing a power diode structure according to the invention is highly efficient at low cost, while providing high reverse and permeable diode parameters in the operating temperature range of -60 ° C to 200 ° C. The high reverse properties of the high-voltage PN junction are achieved diffusion of aluminum into the cut silicon surface is eliminated by forming a recrystallized layer of aluminum-enriched silicon during the brazing process.

The invention is suitable for the manufacture of all types of diodes.

Example

A quartz plate cut from a single silicon crystal is etched unilaterally in a silicone cap in 30% potassium hydroxide, followed by diffusion of aluminum from the deposited aluminum nitrate layer to the non-etched side of the silicon plate at 1250 ° C for 20 hours, followed by two-sided phosphorus temperature of 1230 ° C for 1 hour, after which the silicon wafer is fused with a molybdenum diode electrode using an aluminum-silicon foil of 60 µm thickness in vacuo at 770 ° C.

Claims (1)

Object of the invention 240 040 Process for producing a power diode structure, characterized in that a silicon wafer with a surface / machined silicon mono-crystal cut is etched on one side, aluminum is diffused from the diffusant layer applied to the non-etched side of the silicon wafer at a temperature of 1250? 20 ° C for a maximum of 25 hours ., followed by double diffusion of phosphorus at a temperature of 1200-1250 ° C for up to 3 hours _on, whereupon the silicon wafer soldered side nadífundované aluminum with a molybdenum dilatation electrode with an aluminum foil or aluminum-silicon of thickness 40 to 70 _<4un at 650 to 800 ° C under vacuum or protective atmosphere *