Method for guiding a crack in the peripheral region of a donor substrate

Abstract

The present invention relates to a method for separating solid wafers (1) from a donor substrate (2). The method comprises the steps of: creating modifications (10) within the donor substrate (2) by means of laser beams (12), wherein the modifications (10) define a detachment region along which separation of the solid layer (1) from the donor substrate (2) takes place, and removing material of thedonor substrate (2), starting from a surface (4) extending in the peripheral direction of the donor substrate (2), in the direction of the centre (Z) of the donor substrate (2), in particular for producing an encircling depression (6).

Description

technical field [0001] The invention according to claim 1 relates to a method for separating a solid sheet from a donor substrate. Background technique [0002] In many technical fields such as microelectronics or photovoltaics, materials such as silicon, germanium or sapphire are often used in the form of sheets and plates (so-called wafers). Conventionally, wafers of this type are currently produced by sawing from an ingot, wherein a relatively large loss of material occurs (“kerf loss”). Since the starting materials used are generally very expensive, there is a strong desire to produce such wafers more efficiently and cost-effectively with less material outlay. [0003] For example, with methods commonly used today, almost 50% of the material used is lost as "kerf loss" only in the production of silicon wafers for solar cells. On a worldwide basis, this corresponds to annual losses of more than 2 billion euros. Since the cost of the wafer accounts for the largest share...

AI Technical Summary

Problems solved by technology

[0007] It has been found that although it is possible to produce a modification in a solid at a distance from the edge of the solid with the aid of a laser beam, this is not readily possible in the region of the edge of the solid due to edge effects.

Images