Patent ID: 11891719
Assignee: IVWORKS CO., LTD.
Field: nan (nan)
Classification: CPC nan | IPC C

Claim 11:
12. Method for manufacturing the wafer according to claim 1, comprising the following steps:
a: obtaining a self-supported raw crystal wafer of group 13 element nitride by epitaxial growth,
b: determining the variation of the off-cut angle of said raw crystal at the end of growth, optionally after cutting said crystal, preferably by grinding or by cutting with a wire saw, to a relative thickness greater than 5×10−3 and less than 10−2, said relative thickness corresponding to the ratio of the thickness of the wafer to the largest width of its faces,
c: strain hardening of one face in order to reduce the variation of the off-cut angle, in particular by sandblasting, exposure to laser radiation, shot peening, ion bombardment or another technique making it possible to create a surface mechanical stress on said crystal, so as to obtain a non-zero geometric deflection, in particular a geometric deflection comprised in absolute value between 0.001 and 1, preferably between 0.01 and 0.1 mm/mm of the largest dimension of said wafer
d: after strain hardening, grinding the N face by machining,
e: after strain hardening, grinding the E face by machining,
f: polishing the E face,
g: chemical etching the N face after machining the N face or after polishing the E face,
h: cleaning to decontaminate the surfaces of the wafer
i: preparation of the E face, in particular by plasma engraving, for subsequent deposition of at least one layer necessary for the production of an optoelectronic or electronic component.