Semiconductor - slice cleaving

A method of cleaving a single crystal semiconductor slice including the steps of marking an edge of the slice to produce a localised fracture initiation zone at the edge of the slice, of bending the slice over a cleaving tool positioned to register with said zone until the slice begins to cleave, and of moving, relative the slice, the cleaving tool across the surface of the slice in a direction substantially aligned with the cleavage direction so as to cause the cleavage to propagate from said zone to the opposite edge of the slice, wherein the planar cleaving tool has the form of a planar cleaving blade whose blade edge is curved in the plane of the blade with a radius of curvature that is large compared with its radius of curvature perpendicular to that plane, and wherein the plane of the blade is substantially aligned with said direction of relative movement.

A method of making a plurality of discrete injection laser chips in which a monolithic two-dimensional array of injection laser devices is fabricated in a slice of single crystal semiconductive material by a process that includes the epitaxial deposition of a plurality of semiconductive layers upon a single crystal substrate, in which the slice is cleaved into a plurality of bars each containing a linear array of injection laser devices, and in which the bars are subsequently diced up into individual laser chips, wherein said cleaving of the slice into bars is performed by marking an edge of the slice to produce a set of localised fracture initiation zones at the edge of the slice and, at each of said marks, bending the slice over a cleaving tool positioned to register with that mark until the slice begins to cleave and moving the tool relative the slice across the surface of the slice in a direction substantially aligned with the cleavage direction so as to cause the cleave to propagate from said mark to the opposite edge of the slice, wherein the cleaving tool has the form of a planar cleaving blade whose blade edge is curved in the plane of the blade with a radius of curvature that is large compared with its radius of curvature perpendicular to that plane, and wherein the plane of the blade is substantially aligned with said direction of relative movement.