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What is cleaving? Cleaving is the process of separating a material along its natural crystal planes.
Why cleave materials? Separation along natural planes creates the cleanest edge possible due to the regularity of the materials molecular structure. For semiconductor wafers, cleaved surfaces produce smooth mirrored surfaces that effectively reflect light.
Process: Cleaving is achieved by making a small notch in the edge of a wafer and then applying tensile strain to the notch. This small notch creates a stress concentration that drives crack propagation. If aligned properly, the crack will propagate along crystal planes - the path of least resistance.
The Loomis wafer handling technique avoids problems associated with dice collision and chipping. Unless the wafer holding film grows as dicing takes place, the dice will collide against each other causing chipping.
The colliding and chipping problem is effectively avoided with the Loomis machines by gradually stretching the wafer holding film.
Applications: Creating laser bars, modulators, wave guides, and performing failure analysis