Plasma diagnostic method of multi-amplitude AC bias probe based on data acquisition card

Abstract

The invention belongs to the technical field of plasma, and discloses a plasma diagnostic method of a multi-amplitude AC bias probe based on a data acquisition card. The plasma diagnostic method comprises the steps of: generating AC bias signals based on the data acquisition card, driving the signals via a power amplifier, and applying the signals to a probe in plasma through a sampling resistor, meanwhile, acquiring a voltage signal on the sampling resistor by means of a differential simulation input port of the data acquisition card commanded by a computer, sending the voltage signal to the computer, and converting the voltage signal into a current signal by the computer; and carrying out spectral analysis and least square method fitting, and further calculating to obtain an accurate electronic temperature value and an accurate ion density value. The plasma diagnostic method solves the problem that electronic temperature and ion density measured by adopting the existing fixed-amplitude AC bias probe diagnostic technique are inaccurate, can diagnose the plasma especially insulating deposition environment plasma, can automatically complete the plasma diagnosis process, and output the accurate electronic temperature and ion density values.

Description

technical field [0001] The invention belongs to the field of plasma technology, and relates to a multi-amplitude AC bias probe plasma diagnosis method based on a data acquisition card, which is used for diagnosing plasma, especially plasma in an insulating deposition environment, and obtaining electron temperature and ion density. Background technique [0002] Existing probe technologies for diagnosing plasma parameters are of various types. The most commonly used single probe is to place a small metal electrode, the probe, in the plasma, apply a scanning bias voltage between the probe and the plasma ground electrode, and then measure the change of the probe current with the scanning bias voltage , to obtain the volt-ampere characteristic curve, and then obtain the plasma parameters by analyzing the volt-ampere characteristic curve. In addition, there are double-probe, three-probe and other types. A common feature of these probe technologies is that they all need to add a D...

AI Technical Summary

Problems solved by technology

[0006] The invention provides a multi-amplitude AC bias probe plasma diagnosis method based on a data acquisition card to solve the problem of inaccurate measurement of electron temperature and ion density by the existing fixed-amplitude AC bias probe diagnostic technology, and can Automatically complete the plasma diagnosis process and output accurate electron temperature and ion density values

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