Method and apparatus for creating a w-mesa street

Abstract

A method for fabricating an epitaxial structure includes providing a wafer comprising one or more epitaxial layers. The wafer is divided into dice where the area between the dice are called streets. Each street has a slot formed on either side of the street. The slots penetrate through the epitaxial layer but not the substrate leaving a portion of the epitaxial layer intact between the slots creating a "W" shaped cross section. A protective layer is then formed on the wafer. A laser may be used to singulate the wafer in to individual dice. The laser divides each street between the slots. The barrier walls of the epitaxial layers protect the individual dice from debris created by laser separation.

Description

Technical field [0001] The present disclosure relates to a process used to separate semiconductor dies. Background technique [0002] Semiconductor devices are generally formed as rectangular dies on circular wafers. figure 1 An exemplary wafer 100 including multiple dies 101 (only a few are explicitly numbered) is shown. Exemplary dies 101A and 101B are separated by an area 102 commonly referred to as the "street." Any area between the dies is referred to as a die gap, including vertical and horizontal areas continuing through several dies 101 and any other suitable areas. A laser may be used to separate the dies by cutting the wafer 100 in the die spacing area 102. However, the thermal shock and high temperature caused by the laser may cause part of the wafer to damage the die 101 via "thrown" particles or reformed material. It is desirable to use a die separation method that causes less damage to the die 101. Summary of the invention [0003] It is well known to separate di...

AI Technical Summary

Problems solved by technology

However, the thermal shock and high temperature caused by the laser may cause parts of the wafer to damage the die 101 via "thrown" particles or reformed material.

Images