Ion implantation method for silicon back surface

Abstract

The invention discloses an ion implantation method for a silicon back surface, which is suitable for an ion implantation technique of a thinned silicon back surface. The ion implantation method comprises the following steps: firstly carrying shallow-junction ion implantation on the silicon back surface, wherein the implantation depth can be defined according to the finally required depth and capability of an implantation machine; after the ion implantation is finished, configuring reasonable machine parameters, mainly comprising annealing energy, a scanning overlaying range and the like, by utilizing a laser device; and carrying out laser high-temperature treatment on a thin silicon finishing the implantation so that the final ion distribution spreads and boosts inside. According to the ion implantation method for the silicon back surface, disclosed by the invention, the laser technique has excellent ion distribution environment friendliness, and a subsequent ion distribution curve and a distribution curve when the ion implantation just finishes can be ensured to be consistent, so that the designed depth of the ion distribution is met under the condition of not influencing an ion distribution curve.

Description

technical field [0001] The invention relates to the field of semiconductor integrated circuit manufacturing, in particular to an ion implantation method on the back side of silicon. Background technique [0002] In the manufacturing process of IGBT and other devices, some processes on the back of the silicon are involved, such as the extraction of the collector on the back of the IGBT device. Generally, the back of the silicon wafer needs to be thinned, and the back of the thinned silicon wafer is then implanted with ions as a contact layer. And the field stop layer, but because the backside implantation is performed after thinning, when the thickness of the silicon wafer is reduced to a certain extent, such as 100-300 microns, ordinary high-energy implanters cannot implant such a thin slice. However, when a medium-energy implanter is used for high-energy implantation, not only the output efficiency is greatly reduced, but also it is basically difficult to realize the thin s...

AI Technical Summary

Problems solved by technology

[0002] In the manufacturing process of IGBT and other devices, some processes on the back of the silicon are involved, such as the extraction of the collector on the back of the IGBT device. Generally, the back of the silicon wafer needs to be thinned, and the back of the thinned silicon wafer is then implanted with ions as a contact layer. And the field stop layer, but because the backside implantation is performed after thinning, when the thickness of the silicon wafer is reduced to a certain extent, such as 100-300 microns, the ordinary high-energy implanter cannot implant such a thin slice. However, when using a medium-energy implanter for high-energy implantation, not only the output efficiency is greatly reduced, but it is basically difficult to realize the thin slices that need to be injected with higher energy conditions, and the purchase of new equipment will greatly increase the cost.

Images