Abstract: A method for fracturing semiconductor crystal wafers or bars to form individual chips with active devices without the use of mechanical scribing of the crystal. The method involves forming where fracture is desired a shallow trench by etching in the semiconductor wafer or bar, preferably with sharp corners, or providing over where the fracture is desired the edges of a metallization layer, or both. Applying pressure will then cause the crystal to fracture as a result of strains formed in the crystal at the sharp corners or below the metallization edges. The method is particularly suitable for the fabrication of laser chips from compound semiconductors.

Abstract: An etching composition and method for its use in etching a semiconductor structure, the semiconductor structure comprising a substrate and one or more epitaxial layers. The etching composition comprises a solvent, an etchant, and first and second complexing agents, the etchant and complexing agents being soluble in the solvent. The etchant preferentially etches the substrate with respect to at least one epitaxial layer. The first complexing agent is reactive with the substrate so as to accelerate the rate at which the etchant etches the substrate. The second completing agent is reactive with a component of the at least one epitaxial layer so as to form a resulting compound with the component. This reaction establishes an equilibrium between the resulting compound, the second complexing agent and the component, the equilibrium precluding significant etching of the at least one epitaxial layer.

Abstract: A method for manufacturing a ridge in a channel laser diode in II-VI materials by etching grooves to form an active mesa flanked by support mesas. The method involves using certain etchants for certain compositions of the II-VI layers so that the grooves can be formed by wet chemical etching using only a single photolithographic process.