Testing method and system for automatically measuring semiconductor resistivity and Seebeck coefficient

Abstract

The invention discloses a testing method and system for automatically measuring the semiconductor resistivity and the Seebeck coefficient. The testing method comprises the following steps: putting a sample to be tested in a vacuum environment, heating two ends of the sample to be tested and controlling the temperature difference of the two ends of the sample to be tested; sending a PID (Proportion Integration Differentiation) curve at intervals, wherein the PID curve comprises three temperature points, namely an initial temperature point, a next temperature point to the tested and a preset final testing temperature point, and the PID curve determination principle lies in that the temperature testing interval Delta T=By-Ay, wherein Ay is an initial temperature and By is a next temperature to be tested; acquiring physical quantity data, related to the resistivity and the Seebeck coefficient, of the sample to be tested according to the PID curve till the next temperature to be tested of the PID curve reaches the preset final testing temperature; calculating according to the acquired physical quantity data to obtain the resistivity and the Seebeck coefficient.

Description

technical field [0001] The invention relates to a semiconductor material performance testing technology in the field of material science, in particular to a testing method and system capable of automatically measuring semiconductor resistivity and Seebeck coefficient at different temperatures. Background technique [0002] Thermoelectric materials have the advantages of small size, light weight, no noise, no pollution, etc., which cannot be compared with ordinary mechanical refrigeration or power generation methods. But to date, devices made with thermoelectric materials are far less efficient (<10%) than conventional refrigerators or generators. Therefore, improving the efficiency of thermoelectric materials has become a key part of its research. [0003] The efficiency of thermoelectric materials can be evaluated by defining the thermoelectric figure of merit ZT: [0004] ZT=S 2 Tσ / κ [0005] Among them, S is the Seebeck coefficient (Seebeck coefficient), T is the a...

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Problems solved by technology

[0009] However, the existing test system still has the following defects: a) The measurement of the Seebeck coefficient is limited to single-end heating measurement. After each sample collection is completed, there may be a temperature difference between the two ends of the sample that exceeds 10°C or even greater. The large temperature difference cannot be smoothed in time and effectively, which will affect the minimum interval of temperature point measurement, and it will take a lot of time to smooth the furnace temperature at the next temperature point naturally, and the smoothing effect is not good, which will affect the test accuracy of the next temperature point

Mainly reflected in: ①The control of hardware equipment such as PID, heating at both ends of the sample, vacuuming, etc. stays in manual control, and the operation is complicated and error-prone

② There are defects in the method of automatic collection of criteria, especially in the method of PID control temperature point.

The control of PID in the traditional automatic measurement method is to send all the temperature curves (including dozens of points such as heating and heat preservation) to the PID controller at one time, and start collecting after the temperature in the furnace is stable. This method must Strictly calculate the heating time and holding time of PID, otherwise, the temperature in the furnace will start to collect or the collection has not started. PID has started to work and the temperature will rise to the next temperature point. It is very time-consuming and uncertain to heat up to the next temperature point. Different furnace temperatures lead to differences in heating time and holding time. This causes a large error in the data of each test, and there are many data points sent each time. PID curve setting error rate is high

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