Cast single crystal seed crystal preparation method

Abstract

The invention discloses a preparation method of a cast single crystal seed crystal. The preparation method comprises the following steps: removing the head and the tail of a straight-pull single crystal rod; defining the cutting surface of the head of the straight-pull single crystal rod as a head surface, and defining the cutting surface of the tail of the straight-pull single crystal rod as a tail surface; carving a T-shaped mark on the head surface through a diamond pen, wherein the upper ridge, the lower ridge, the left ridge and the right ridge of the T shape are a, b, c and d respectively; forming a square by a, b, c and d by seeing from the front view of the head surface angle, rotating the square by an angle X by taking the circle center of the head surface as a reference, and performing peeling operation to obtain a single crystal square rod, wherein the four side surfaces of the single crystal square rod are respectively defined as a No.1 surface, a No.2 surface, a No.3 surface and a No.4 surface; carving a vertical line on the left side or the right side of the No.1 surface by using a diamond pen to serve as a marking line; and transversely cutting the single crystal square rod into a plurality of single crystal seed crystals with the same height from the head surface to the tail surface, and finally cleaning the X single crystal seed crystals.

Description

technical field [0001] The invention belongs to the field of single crystal seed crystal preparation technology, and in particular relates to a method for preparing a cast single crystal seed crystal. Background technique [0002] In the existing technology, after the single crystal square bar is cut into cast single crystal seed crystals, marking is made on each cast single crystal seed crystal. At this time, it is not easy to distinguish the head (or front) and tail (or reverse side), No. 1 side, No. 2 side, No. 3 side, and No. 4 side. Different types of cast single crystal seeds are also easy to mix, because each single crystal seed crystal is a square block with the same size and shape, and it is difficult to distinguish the head. head and tail. The existing marking method is to make a mark on each single crystal seed. For example, the X single crystal seed is marked with "X" at a certain position, and the Y single crystal seed is marked with "Y" at a certain position. ...

AI Technical Summary

Problems solved by technology

[0002] In the existing technology, after the single crystal square bar is cut into cast single crystal seed crystals, marking is made on each cast single crystal seed crystal. At this time, it is not easy to distinguish the head (or front) and tail (or reverse side), No. 1 side, No. 2 side, No. 3 side, and No. 4 side. Different types of cast single crystal seeds are also easy to mix, because each single crystal seed crystal is a square block with the same size and shape, and it is difficult to distinguish the head. head and tail

The existing marking method is to make a mark on each single crystal seed. For example, the X single crystal seed is marked with "X" at a certain position, and the Y single crystal seed is marked with "Y" at a certain position. The amount of marking is large. Labeling of each monolithic cast single crystal seed is prone to error

[0003] The cast single crystal seed crystal is cleaned with mixed acid (hydrofluoric acid + nitric acid), because the mixed acid reacts violently with the cast single crystal seed crystal, which often leads to uneven reaction on the surface of the cast single crystal seed crystal, and also leads to The size deviation between the seed crystals is large, and the production of cast single crystal silicon ingots with cast single crystal seed crystals with large size deviations will seriously affect the quality of cast single crystal silicon ingots

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