A Comparison of Residual Stress Induced by Fixed Abrasive Diamond Wire Sawing and Loose Abrasive Slurry Wire Sawing in Multicrystalline Silicon Wafers
At a Glance
Section titled āAt a Glanceā| Metadata | Details |
|---|---|
| Publication Date | 2016-01-01 |
| Journal | EU PVSEC |
| Authors | Vanessa Pogue, Shreyes N. Melkote, R.G.R. Prasath, S. Danyluk |
Abstract
Section titled āAbstractāThe breakage of thin Silicon (Si) wafers is a significant problem that leads to lower production yields in the manufacture of Si-based solar cells. Residual stress of Si wafers is therefore a major concern due to its detrimental effect on wafer mechanical integrity. This work investigates the spatial distribution of residual stress in multicrystalline silicon (mc-Si) wafers produced by the two prevalent wire sawing methods used in industry: loose abrasive slurry wire sawing (LAWS) and fixed abrasive diamond wire sawing (DWS). The saw damage layer of ascut industrially sawn DWS and LAWS wafers was removed at 2 Ī¼m steps using wet chemical isotropic etching and residual stress was measured as a function of etch depth using a near-infrared birefringence polariscope. Results show that in as-cut wafers, DWS creates a larger number of high maximum residual shear stress locations compared to LAWS. In DWS, points of highest residual stress were aligned with wire striation lines in the direction of wire travel. In contrast, LAWS resulted in a random pattern of locations of high residual stress. After 12 Ī¼m of material removal by etching, the points of highest residual stress were localized at grain boundaries in both DWS and LAWS wafers.