Method for detecting dislocation density of semiconductor chip

Abstract

The invention discloses a method for detecting dislocation density of a semiconductor chip, which relates to the field of detection of a semiconducting material. The method comprises the following steps: a corroded sample is placed on a white-light interferometer for being scanned, scanning marginheight and scanning spot number are set; the images are gradually scanned: each image is subjected slightly adjusted, the interferometric fringe is more intelligible and obvious; automatic statistics for data is carried out: the dislocation etch pits are automatically indentified, the quantity of the dislocation etch pits in each image can be automatically counted, the dislocation density is calculated; a test report is generated: a dislocation density measurement report comprises view field number, magnification times, a chip detecting dislocation distribution map, and dislocation counting and the dislocation density of all view fields, and the dislocation density of the semiconductor chip is an average value of the dislocation density of all view fields. The method realizes the automatic statistics and analysis of the dislocation density, and has the advantages of high scanning accuracy and fast analysis speed.

Description

technical field [0001] The invention relates to the field of semiconductor material detection, in particular to a method for detecting the dislocation density of a semiconductor wafer. Background technique [0002] There are many types of semiconductors. Commonly used elemental semiconductors are silicon and germanium. Commonly used III-V compound semiconductors are gallium arsenide and indium phosphide. Compound semiconductors are usually direct bandgap semiconductors and have a wide range of applications. In the process of preparing semiconductor materials, dislocations will be generated due to thermal stress, which will affect the quality of epitaxial layers and devices, so it is necessary to accurately measure the dislocation density of the wafer. The conventional method for measuring the dislocation density is to etch the wafer first, then scan the wafer with a metallographic microscope, and then manually count the dislocation pits on each image. The corrosion pit of I...

AI Technical Summary

Problems solved by technology

Since the metallographic microscope cannot distinguish the vertical depth of the corrosion pit, it can only be manually judged by the two-dimensional surface pattern of the S pit and the D pit. Usually, it is necessary to manually distinguish the image point by point, which is time-consuming, laborious, and inconvenient. Pit and S pits are also more difficult, so there are large errors in statistics

For wafers with low dislocation density, it is easy to cause missing numbers with traditional metallographic microscopes, and the measured value deviates greatly from the actual value.

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