Technological method for adjusting barrier height of Schottky diode by doping silicon dioxide film

Abstract

A technological method for adjusting the barrier height of a Schottky diode by doping a silicon dioxide film comprises the steps that an N-type single crystal silicon substrate and an N-type single crystal silicon epitaxial layer chip are used as materials, an oxide layer is formed on an N-type single crystal silicon epitaxial layer to be used as a passivation layer, and the thickness of the oxide layer is larger than 400 nanometers; a doping window is formed by primary photoetching; an ion implantation technology is adopted in the doping window for conducting boron doping, and meanwhile the oxide film is grown to form a P-type protecting ring; the main surface of a Schottky barrier window is formed by secondary photoetching; an oxide layer which is doped with the silicon dioxide film and has the surface thickness of 50-300 nanometers is formed on the main surface of the Schottky barrier window in a deposition mode, rapid annealing is conducted under the nitrogen atmosphere to push impurities doped in silicon dioxide towards the N-type single crystal silicon epitaxial layer, and a thin variable doping layer is formed between the oxide layer of the silicon dioxide and the main surface of the N-type epitaxial layer. The barrier height is lowered through the thin variable doping layer.

Description

technical field [0001] The invention relates to the field of manufacturing semiconductor power devices, in particular to a method for manufacturing a Schottky rectifier diode. More specifically, the present invention relates to a process method for adjusting the height of Schottky diode barrier by changing the silicon surface concentration by doping silicon dioxide to form an extremely thin variable doped layer. Background technique [0002] Schottky barrier diodes have low forward voltage drop and high switching speed, and are widely used in low-voltage circuits, but unfortunately, Schottky barrier diodes have a large reverse leakage current at high temperatures, and the reverse leakage The current increases exponentially with temperature, and high temperature power consumption and reliability pose challenges. [0003] In order to solve the problem of high temperature leakage of Schottky barrier diodes, there are currently three main ways, one: increase the barrier height ...

AI Technical Summary

Problems solved by technology

When the number of implanted impurity ions is very small, it is difficult to control the implantation uniformity and process repeatability, and the traditional process method of adjusting the barrier height of Schottky diodes by using an extremely small dose ion implantation process is rarely applied on a large scale

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