Research On Evolution Of Ionization-induced Defects In Gated Lateral Bipolar Transistors At Different Radiation Temperatures

Three GLPNP transistors with different structures were irradiated with ?-ray at different temperatures(room temperature,50?,75?,100?,125?,150?,200?).By comparimg the electrical properties and ionizing-induced defects of GLPNP transistor irradiated at different temperatures,the evolution of ionizing-induced defects in GLPNP bipolar transistors at different temperature is systematically studied,and the effect of ionizing-induced defects on the electrical properties in the transistors is revealed.The experimental results show that the radiation damage of the transistors at different temperatures are different.With the same radiation dose,when the temperature is less than 200?,?(1/?)increases with increasing temperature;but it decreases when the temperature reaches 200?.The Gummel curve indicates that the difference between ?(1/?)at different temperatures is mainly caused by the change of the base current,and is basically independent of the collector current.The oxide trapped charge and interface state of the GLPNP transistors characterrized by GS and SS technique could achieve good agreement,and GS technology is more intuitive and easier to calculate than SS technology.DLTS analysis can detect the concentration of the interface state accurately,but it cannot detect the shallow oxide trapped charge.The ionizing-induced defects characterized by three different techniques show that the oxide trapped charge decreases with increasing temperature within the range from room temperature to 200 ?;while the change of the interface state with temperature is consistent with that of ?(1/?).Therefore,the oxide trapped charge can anneal at any temperature above room temperature,while the interface state cannot anneal obviously unless the temperature up to 200?.The interface state is the main factor that affect the degradation of the transistor.The difference between ?(1/?)of three different GLPNP transistors at different temperatures is the result of the combination of the base current and the collector current.At room temperature,the recombination in the space charge region dominates,so the difference of ?(1/?)between three different transistors is mainly affected by the ratio of the circumference to the area of the emitter.Increasing temperature will lead to the reduction of recombination in the space charge region and the increase of recombination in the neutral base area,so the difference of ?(1/?)between three different transistors is the result of the combination of the base area and the ratio of the circumference to the area of the emitter.