Method for detecting concentration of impurities in ultra-high-purity germanium rod or ingot

Abstract

The invention provides a method for detecting the concentration of impurities in an ultra-high-purity germanium rod or ingot. According to the invention, a direct-current two-probe method is used fordetecting impurity concentration; the germanium rod or ingot is detected at a constant temperature of 77 K; any measurement point in the radial length of the germanium rod or ingot is coated with indium-gallium alloy; two probes measure equal-distance voltage drop U, and resistivity rho is calculated according to the function relation that rho is equal to (U+S) / (I*L); and then the average net impurity concentration n of the germanium rod or ingot between the probes is calculated according to the equation that n is equal to rho*q*mu. The method provided by the invention overcomes the problem that the integral impurity concentration of a germanium rod or ingot cannot be detected in the prior art, guarantees the integrity of a to-be-detected sample, and is accurate in detection results, highin detection efficiency and beneficial for industrialization.

Description

technical field [0001] The invention relates to the field of detection of semiconductor germanium rods or ingots, in particular to a method for detecting the impurity concentration of ultra-high-purity germanium rods or ingots. Background technique [0002] The germanium products currently on the market are generally purified by zone melting after chemical purification, and finally reach a purity of 5-6N after pulling a single crystal. Because the impurity content of germanium samples with a purity lower than 6N is different from that at room temperature (23±5°C) Resistivity has a certain corresponding relationship, so the current detection requirements for this purity germanium product are mainly electrical properties, that is, the size of resistivity. [0003] For zone-melted germanium ingots, the volume resistance is usually measured by two-probe resistivity detection method at room temperature (23±5°C). At present, there are relevant standards for two-probe resistivity d...

AI Technical Summary

Problems solved by technology

However, the single low-temperature Hall detection method is only suitable for testing thin flake samples. For crystal rods, the section must be sliced ​​and cleaned before measurement, which is too inefficient, and there is no objective basis for selecting the slice point, which has a certain blindness

Therefore, low-temperature Hall detection is feasible as a confirmatory final test, but it cannot detect the overall impurity concentration of rod-shaped or ingot-shaped ultra-high-purity germanium products

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