Single-Step multiple-layers wafer slicing from macroporous silicon

Abstract

There is a rising interest, from both photovoltaics and microelectronics industry, in wafer thickness reduction. During the last decade, it has been steadily reduced from 350 µm to 180 µm, but benefits are foreseen for thicknesses well below these values. The current sawing technology, however, suffers from large kerf losses and further reductions are increasingly difficult. Several technologies have emerged aiming to produce thin Si foils from a wafer, such as layer transfer, induced cleaving, or pore reorganization. These methods produce a single layer by step. In this work we report on a method able to produce many crystalline layers from a single silicon wafer and in a single fabrication step.