Introduction

Silicon carbide is superior to silicon in some applications as it has higher thermal conductivity, a wider band gap, is thermally and chemically inert, and features a higher breakdown field. These characteristics make it appealing for use in transistors (JFETS, MOSFETs, etc.), for applications like high temperature electronics, as well as in rapid high voltage devices for more effective power transmission. At present, it is utilized in a range of fields, including next generation power electronics for transportation solutions.

Challenges Facing Silicon Carbide

Silicon carbide's properties depend on its crystal structure (it can exist in a number of polytypes), on the crystal quality, and on the types and number of defects present. Silicon carbide raw material and device manufacturers must regulate and control these properties to improve their yield.

The Power of Raman Spectroscopy

As a first step in controlling these parameters, they need to be determined repeatably and in a quantifiable manner. The Raman systems from Renishaw are the ideal solution for this. The analysis of laser light scattered from the silicon carbide enables the quality, the crystal form, and the nature of defects to be determined.

This can be done conveniently, rapidly and in a non-destructive manner. A small region or a complete wafer can be analyzed, and both surface and subsurface information can be revealed in three dimensions.

Key Features of Renishaw’s Raman Systems

The key benefits of using Renishaw’s Raman systems for SiC analysis are:

• The crystal polymorphs and polytypes present can be determined

• Their distribution can be revealed

• The complex defects in three dimensions can be analyzed

• Depth profiles, interfaces, and layers can be studied

• It can be used for both development and as FA, QA tools

• Stress or strain can be determined

• Measurement of electronic properties, such as free carrier concentration and dopant levels is possible

• Rapid mapping of large wafers possible

The key features of the inVia are:

• Research grade Raman microscope

• High confocality StreamLineHR™ imaging for observing minute details

• Flexibility of switching between standard and high confocal imaging

• Measurements can be lined up to maximise data collection

• StreamLine™ imaging technology for high speed mapping, including whole wafers

• Surface option for acquiring superior quality images from uneven surfaces

• StreamLine imaging with Slalom for obtaining a general idea of the samples