METHOD FOR SERVERING AN EPITAXIALLY GROWN SEMICONDUCTOR BODY, AND SEMICONDUCTOR CHIP
A method for severing an epitaxially grown semiconductor body is given, in which a) a growth substrate ( 2 ) is provided; b) at least one trench ( 20 ) is produced in a first main surface ( 2 a ) of the growth substrate ( 2 ) by etching; c) a semiconductor material is epitaxially deposited on the first main surface ( 2 a ) and in the trench ( 20 ), wherein a semiconductor body ( 1 ) is formed, and the semiconductor body at least partially fills the trench ( 20 ); and d) the semiconductor body and the growth substrate are cut along the main direction of the trench. Furthermore, a semiconductor chip with a cover surface and side surfaces is specified, in which the side surfaces each have a beveled section that is adjacent to the cover surface and whose surface is created by epitaxy.
1 . A method for severing an epitaxially grown semiconductor body, wherein
a) a growth substrate is provided;
b) at least one trench having a main extension direction is produced in the growth substrate by etching from a first main surface of the growth substrate;
c) a semiconductor material is epitaxially deposited on the first main surface and in the trench, wherein a semiconductor body is formed which at least partially fills the trench; and
d) the semiconductor body and the growth substrate are severed through the trench along the main extension direction.
2 . The method according to claim 1 , wherein exclusively the trench defines a predetermined breaking point for the severing.
3 . The method according to claim 1 , wherein
in method step b) a mask is arranged on the first main surface of the growth substrate), and
the mask has a window through which the trench is etched.
4 . The method according to claim 1 , wherein
after method step c) the semiconductor body has a depression on a front side facing away from the growth substrate, and
the depression overlaps with the trench in growth direction of the semiconductor body and has a v-shaped cross-section perpendicular to the main extension direction of the trench.
5 . The method according to claim 1 , wherein
after method step c) the semiconductor body has a recess in the trench.
6 . The method according to claim 5 4 , wherein the recess is limited on all sides by the material of the semiconductor body.
7 . The method according to claim 4 , wherein
an absorber structure is arranged in the recess,
the absorber structure is formed with an absorber material having a higher absorption capacity for electromagnetic radiation in a predetermined wavelength range than the material of the semiconductor body and/or the growth substrate,
in method step d) the absorber structure is heated by irradiation.
8 . The method according to claim 7 , wherein the absorber structure and regions of the semiconductor body and the growth substrate adjacent to the absorber structure are irradiated.
9 . The method according to claim 7 , wherein the absorber structure projects beyond the semiconductor body in a growth direction of the semiconductor body.
10 . The method according to claim 7 , wherein
the absorber structure completely covers a bottom surface of the trench.
11 . The method according to claim 4 , wherein
an expansion structure is arranged in the recess, wherein
the expansion structure is formed with an expansion material, wherein the expansion material has a larger coefficient of thermal expansion than the material of the semiconductor body and/or the growth substrate,
in method step d) the temperature of the compound comprising the semiconductor body, the growth substrate and the expansion structure is changed, and
the compound with the semiconductor body and the growth substrate is severed along the expansion structure.
12 . The method according to claim 1 , wherein
in method step b), a plurality of trenches is produced in the growth substrate, the main extension directions of these trenches extend along grid lines of a virtual periodic grid, which is located in the first main surface of the growth substrate.
13 . The method according to claim 12 , wherein
the plurality of trenches comprises first trenches and second trenches,
the main extension direction of first trenches is transverse to the main extension direction of second trenches, and
first trenches and second trenches do not cross each other.
14 . A semiconductor chip with a cover surface and a plurality of side surfaces, wherein
the side surfaces each have a beveled section, wherein
the beveled section is adjacent to the cover surface, and
the surface of the beveled section is created by epitaxy.
15 . The semiconductor chip according to claim 14 , in which the side surfaces comprise absorber material and/or expansion material.
16 . A method for severing an epitaxially grown semiconductor body comprising
a) providing a growth substrate;
b) producing at least one trench having a main extension direction in the growth substrate by etching from a first main surface of the growth substrate;
c) epitaxially depositing a semiconductor material on the first main surface and in the trench, wherein a semiconductor body is formed which at least partially fills the trench; and
d) severing the semiconductor body and the growth substrate through the trench along the main extension direction, wherein
after method step c) the semiconductor body has a recess in the trench,
a separating element is arranged in the recess,
the separating element is configured to exert a separating force on the semiconductor body and/or growth substrate by thermal expansion, and
in method step d) the semiconductor body and the growth substrate are severed by the separating force.