Doping device for heavily doping czochralski single crystal

Abstract

The invention discloses a doping device for heavily doping a czochralski single crystal. The side wall of a quartz bell jar in the doping device consists of a plurality of layers of quartz walls, a plurality of holes are respectively formed in the plurality of layers of quartz walls on the inner side of an outer wall, and the holes in two adjacent layers of quartz walls are distributed in a mutually staggered manner, wherein the arrangement mode of the plurality of layers of quartz walls is as follows: the starting point of the top descends layer by layer from inside to outside. Preferably, two layers of quartz walls are arranged on the inner side of the outer wall. According to the doping device, the structure of the quartz bell jar is improved, so that the thermal motion mode of doped gas molecules is changed, and the doped gas molecules can exist in the quartz bell jar for a longer time. Under the same doping time and conditions, the doped gas molecules can be dissolved into a silicon material more easily, and the doping efficiency can be remarkably improved.

Description

technical field [0001] The invention relates to a doping device for heavily doped Czochralski single crystal, belonging to the technical field of single crystal silicon pulling. Background technique [0002] At present, semiconductor silicon materials can be divided into heavily doped silicon single crystals and lightly doped silicon single crystals. The resistivity value of the pulled single crystal is determined by the doping amount of the selected doping element, the greater the doping amount of the doping element, the lower the resistivity of the single crystal. A low-resistivity single crystal with a large amount of doping is called a heavily doped silicon single crystal; on the contrary, a small amount of doping elements is called a lightly doped silicon single crystal. [0003] Among them, heavily doped silicon single crystal is the most ideal epitaxial substrate material, and its market demand continues to increase. The mainstream process of modern ultra-large-scal...

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Problems solved by technology

[0007] 1. After sublimation of arsenic at high temperature, the gas molecules volatilize rapidly, and the gas molecules continue to move around at high temperature (such as figure 1 (indicated by the middle arrow), and after hitting the quartz bell jar, it rushes back to the liquid surface, and a large part of the gas molecules that have not yet been integrated into the silicon material will be lost from the gap between the quartz bell jar and the liquid surface, reducing the doping efficiency

[0008] 2. Volatile matter will adhere to the vacuum pipeline, and after a long time, it will partially block the pipeline, affecting the normal operation of the vacuum system, making the atmosphere unsmooth and affecting crystal formation, and the arsenic that is drawn away is also a harmful and toxic substance that causes harm to the outside world

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