Papers by Keyword: Bipolar Transistors

Abstract: The electronic systems of aerospace techniques include power microwave devices and analog and digital semiconductor devices. The radiation of power microwave devices may effect on the semiconductor devices. So it’s necessary to know the electromagnetic effects of this radiation on the semiconductor devices. The electromagetic effects of the microwave radiation exposure on the semiconductor diodes, the main part of any semiconductor devices, are considered. The changes of current – voltage characteristics of the diodes are explained, outgoing from the model of the recombination of carriers through deep energy level recombination center in forbidden gap induced by microwave radiation field.

Abstract: Integrated circuits are used in electronic equipment of spaceships. Therefore, they are impacted by ionizing radiation during space mission. It leads to electronic equipment failures. At present operational amplifiers are base elements of analog electronic devices. Radiation impact leads to degradation of operational amplifiers input stages. Input bias current increasing and input offset voltage drifts are the results of ionizing radiation expose of operational amplifiers. Therefore, space application electronic equipment fails after accumulation of limit dose. It isn’t difficult to estimate radiation degradation of input bias currents of bipolar operational amplifiers, but estimation of dose dependence of input offset voltage drift is more complex issue. Schematic modeling technique based on Gummel–Poon transistor model for estimation of input offset voltage drift produced by space radiation impact was experimentally verified for LM324 operational amplifier and presented in this work. Radiation sensitive parameters of Gummel–Poon model were determined using 2N2907 bipolar pnp transistor.

Abstract: Ionizing radiation impact leads to degradation of electrical parameters of microelectronic devices. It is necessary to take this fact to account when dealing with microcircuits for space applications and high energy physics. Main physical reason of radiation-induced failures of spaceship and front end electronic equipment is buidup of interface traps at Si-SiO₂ interface in semiconductor transistor structures. The original mechanism of interface trap annealing based on radiation induced charge neutralization (RICN) effect is presented. It is supposed that the positive charge of trapped holes in oxide is transformed through electron capture into a new defect (the AD center). The AD centers act as interface traps. The appearance of the A^–D⁺ state leads to the annihilation of the AD center or annealing of interface trap. The annihilation process can be stimulated by radiation induced or substrate electrons. The competitive between accumulation and annihilation processes leads to saturation of the interface trap buildup. The value of density of interface trap in saturation depends on product of interface trap accumulation rate (K_acc)_it and constant K_AD which is function of thermal velocity, capture cross-section of AD center, generation rate and electron yield of radiation induced electrons. The extraction of these parameters allows explaining a known experimental data. The alternative mechanism of the interface trap saturation connected with the exhaustion of initial interface trap precursors is considered.

Abstract: In this study, we report on the observation of recombination center defects in the base of 4H-SiC bipolar junction transistors. The defects are observed through a very sensitive electrically detected electron spin resonance technique called spin dependent recombination. To the best of our knowledge, these results represent the first electron spin resonance results of any kind reported in a fully processed SiC bipolar junction transistor and provide the first direct observations of the chemical and physical nature of recombination centers in SiC bipolar junction transistors. Our results clearly demonstrate the power of SDR techniques in the detection of recombination centers in SiC bipolar junction transistors.