Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
201 words
A method of manufacturing oriented substrate plates of a III-V-material, which comprises: (a) forming a monocrystalline pulling nucleus of the III-V material having crystallographic axes OU, OV and OZ which axes form an orthonormal system; (b) pulling according to the Czochralski method a monocrystalline ingot of the III-V-material using the nucleus with its axis OZ parallel to the pulling direction; (c) shaping the ingot into the form of a more perfect cylinder with its axis parallel to the axis OZ; (d) determining by X-ray diffraction the direction of the crystallographic axes OU and OV of the ingot which form with the axis OZ an orthonormal system; (e) shaping on the ingot a major flat perpendicular to the axis OU and a minor flat perpendicular to the axis OV and (f) cutting substrate plates from the ingot perpendicular to the axis OZ, characterized in that, (g) during step (a) the seed crystal further is shaped into the form of a rectangular prism with flat perpendicular to its crystallographic axis OU and OV, which flats then are slightly etched in an etching bath which preferentially attacks the III-V-material and (h) during steps (c) and (d) the seed crystal remains attached to the ingot.
Claim 2
Independent Claim
201 words
A method of manufacturing oriented substrate plates of a III-V-material, which comprises: (a) forming a monocrystalline pulling nucleus of the III-V material having crystallographic axes OU, OV and OZ which axes form an orthonormal system; (b) pulling according to the Czochralski method a monocrystalline ingot of the III-V-material using the nucleus with its axis OZ parallel to the pulling direction; (c) shaping the ingot into the form of a more perfect cylinder with its axis parallel to the axis OZ; (d) determining by X-ray diffraction the direction of the crystallographic axes OU and OV of the ingot which form with the axis OZ an orthonormal system; (e) shaping on the ingot a major flat perpendicular to the axis OU and a minor flat perpendicular to the axis OV and (f) cutting substrate plates from the ingot perpendicular to the axis OZ, characterized in that, (g) during step (a) the seed crystal further is shaped into the form of a rectangular prism with flat perpendicular to its crystallographic axis OU and OV, which flats then are slightly etched in an etching bath which preferentially attacks the III-V-material and (h) during steps (c) and (d) the seed crystal remains attached to the ingot.
Claim 3
Dependent Claim
52 words
A method as claimed in claim 1, characterized in that, when forming the prism, a recess is provided in the form of a facet breaking one edge of the prism and in that this recess serves at the same time as a recess for fixing the seed crystal in the pulling assembly.
Claim 4
Dependent Claim
51 words
A method as claimed in claim 2, characterized in that, when forming the prism, the flats of the prism are set perpendicular to the crystallographic axes OU and OV, and the edge which is provided with the recess, is situated in the bisector plane of the two crystallographic axes OU, OV.
Claim 5
Dependent Claim
64 words
A method as claimed in claim 2, characterized in that, when forming the prism, the flats of the prism are set in such a way that one of the characteristic axes OU or OV is situated in their bisector plane, and in that edge which is provided with the recess is situated in the bisector plane containing one of the axes OU or OV.
Claim 6
Dependent Claim
55 words
A method as claimed in claim 3, characterized in that the semiconductor material is gallium arsenide (GaAs) and in that the preferential etching bath is composed of 5 volumes of sulphuric acid, 1 volume of hydrogen peroxide, 1 volume of water, and in that the pulling nucleus is immersed in said bath for 2 minutes.
Claim 7
Dependent Claim
55 words
A method as claimed in claim 4, characterized in that the semiconductor material is indium phosphide (InP), and in that the preferential etching bath is composed of 1 volume of sulphuric acid, 1 volume of hydrogen peroxide, 1 volume of water; and in that the pulling nucleus is immersed in said bath for 2 minutes.
Claim 8
Dependent Claim
18 words
A method as claimed in claim 1, characterized in that the pulling axis OZ is the (001) axis.
Claim 9
Dependent Claim
26 words
A method as claimed in claim 7, characterized in that the chosen characteristic axis OU and OV are the axes (110) and (110) of the crystal.
Claim 10
Dependent Claim
34 words
A method as claimed in claim 8, characterized in that the major flat is formed perpendicularly to the (110) axis and the minor flat is formed perpendicularly to the axis (110) of the crystal.