Research on Transient Temperature Rise Measurement Method for Semiconductor Devices Based on Photothermal Reflection

In this article, a transient temperature rise measurement method for semiconductor devices based on photothermal reflection is proposed. The relationship between the reflectivity of a 360 nm laser beam and the device temperature is studied. Through the appropriate design of the optical circuit and the data acquisition system, measurement of the transient temperature rise characteristics of GaN-based microwave power devices is realized. In combination with resistor-capacitor network impulse response theory, the transient temperature rise curve is processed using the Bayesian iterative deconvolution method. By extracting the thermal time constant, nondestructive characterization of the temperature increase and thermal resistance characteristics of each material layer in the heat flow path is achieved, and the complementary relationship between the temperature change in the active region during heating and the device heat dissipation characteristics is verified. Additionally, the forward Schottky junction characteristics method and infrared thermal imaging are used to measure the channel temperature for verification of the proposed thermal reflection method. These measurements indicate that the proposed method can provide accurate results.