Effect of Abrasive Grit Shape on Surface Morphology, Subsurface Damage and Fracture Strength of Diamond Wire Sawn Silicon Wafers
At a Glance
Section titled āAt a Glanceā| Metadata | Details |
|---|---|
| Publication Date | 2016-01-01 |
| Journal | EU PVSEC |
| Authors | Chris Arcona, S. KamiÅski, Shreyes N. Melkote, A. Senthil Kumar |
| Citations | 4 |
Abstract
Section titled āAbstractāThe surface morphology of and subsurface damage in silicon wafers produced by fixed abrasive diamond wire sawing influence the mechanical strength of photovoltaic silicon solar cells. One approach to cutting wafers with favorable surface and subsurface characteristics is using diamond wires made with different grit shapes. In this paper, we study mono-crystalline silicon wafers cut by wires with two nominally different grit shapes (denoted A and B), to determine the effect of grit shape on the wafer surface morphology, roughness, subsurface damage, and fracture strength. It is found that the surface morphology of wafers cut by wire A exhibits more ductile grooves while the wafer surface cut by wire B exhibits more brittle fracture. The surface roughness data show that wafers cut by wire A have lower surface roughness than those cut by wire B. However, biaxial flexure tests on laser-cut wafer coupons show that the wafers cut by wire A have lower fracture strength than those cut by wire B. The subsurface damage in wafers cut by wire A consists of fewer but longer median cracks than those cut by wire B, which has shallow median and lateral cracks. We hypothesize that the observed variation in fracture strength results from the dominance of the subsurface condition over the surface condition.