Method for manufacturing silicon carbide high-temperature ion implantation mask with selectivity cut-off layer

Abstract

The invention discloses a method for manufacturing a silicon carbide high-temperature ion implantation mask with a selectivity cut-off layer. The method includes the steps of cleaning a silicon carbide substrate, adopting a heat oxidation method to grow an ion implantation sacrificial layer mask on the silicon carbide substrate, adopting an LPCVD method to grow the selectivity cut-off layer used for controlling the etching process on the obtained ion implantation sacrificial layer mask, adopting an epitaxy or growing method to form an insulating medium masking layer on the selectivity cut-off layer, evenly coating the insulating medium masking layer with photoresist, carrying out photoetching to develop a selectivity ion implementation area window, carrying out dry-method etching or corrosion on the insulating medium masking layer from the selectivity ion implementation area window to the surface of the selectivity cut-off layer, continuously carrying out etching or corrosion to the surface of an ion implantation sacrificial layer, removing the photoresist, and obtaining the ultra-thin ion implementation sacrificial layer mask. The method for manufacturing the silicon carbide high-temperature ion implantation mask is suitable for a silicon carbide SBD, a JBS diode, an MOSFET device and other silicon carbide devices requiring high-temperature high-energy ion implantation.

Description

technical field [0001] The invention relates to the fields of ion implantation mask preparation technology and etching / corrosion technology, in particular to a method for manufacturing a silicon carbide (SiC) high temperature ion implantation mask with a selective cut-off layer. Background technique [0002] Silicon carbide material has excellent physical and electrical properties. With its unique advantages such as wide band gap, high thermal conductivity, large saturation drift velocity and high critical breakdown electric field, it has become a high-power, high-frequency, durable It is an ideal semiconductor material for high-temperature and radiation-resistant devices, and has broad application prospects in military and civil affairs. Power electronic devices made of SiC materials have become one of the hot devices and frontier research fields in the field of semiconductors. [0003] Mask technology is one of the important processes in semiconductor manufacturing, and i...

AI Technical Summary

Problems solved by technology

This method is not only complicated in process, but also the formed ion implanted sacrificial layer film is affected by the thick medium ion implanted mask layer, which has poor in-plane uniformity and controllability, which seriously affects the doping distribution of the selective ion implanted region, thus affecting The breakdown characteristics of the device; 2) The ion implantation sacrificial layer is first formed by thermal oxidation, and then the high temperature ion implantation masking layer is deposited, and etched to the surface of the ion implantation sacrificial layer by etching

This method is feasible, but the etching technology is not easy to control

The wet etching rate is slow, and the etching is isotropic, and it is difficult to form a steep etching sidewall

Dry etching, usually using ICP etching, can form steep sidewalls, but because the ion implantation sacrificial layer is very thin, and the etching selectivity ratio to the masking layer is not high, over-etching is easy to occur during the etching process Corrosion phenomenon, causing damage to the device surface

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