China
Africa
Explore chapters and articles related to this topic
Basics of Semiconductor Detector Devices
Published in Douglas S. McGregor, J. Kenneth Shultis, Radiation Detection, 2020
Douglas S. McGregor, J. Kenneth Shultis
The topic of avalanche breakdown was discussed earlier in Sec. 14.2.3. Indeed, some light detection devices were seen to rely upon this effect for gain. However, avalanche breakdown can become a source of unwanted noise and can also cause irreparable damage to semiconductor detectors. The breakdown occurs when electrons gain enough kinetic energy from an applied electric field such that some of their energy can be transferred to the lattice and excite more electrons into the conduction band.
Review of Fundamentals Related to DC Power Supply Design and Linear Regulators
Published in Nihal Kularatna, DC Power Supplies Power Management and Surge Protection for Power Electronic Systems, 2018
The most common and simple way to achieve a reference source is to use a reverse-biased diode, or a zener diode as it is commonly called, where it enters into a voltage breakdown region. A zener diode has two distinctly different breakdown mechanisms: zener breakdown and avalanche breakdown. The zener breakdown voltage decreases as the temperature increases creating a negative temperature coefficient (TC). The avalanche breakdown voltage increases with temperature (positive TC). This is illustrated in Figure 1.8. The zener effect dominates usually below 5 V, and the avalanche effect dominates above 6 V. By the use of additional diode (in forward-biased mode) in series with an avalanche-type diode, it is possible to achieve a better temperature stability in a reference circuit [5]
Reliability in III-Nitride Devices
Published in Wengang (Wayne) Bi, Hao-chung (Henry) Kuo, Pei-Cheng Ku, Bo Shen, Handbook of GaN Semiconductor Materials and Devices, 2017
Davide Bisi, Isabella Rossetto, Matteo Meneghini, Gaudenzio Meneghesso, Enrico Zanoni
Avalanche breakdown is caused by the generation of electron-hole pairs and the current multiplication due to impact ionization. Impact ionization happens when free electrons traveling through a high field region undergo scattering events and transfer excess energy to bonded electrons in the valence band, lifting them into the conduction band, creating new electron-hole pairs, and increasing the free carrier density; generated holes can at their turn contribute to impact ionization. Impact-ionization coefficient in gallium nitride has been theoretically predicted by means of Monte Carlo calculation [180] and experimentally reported in AlGaN/GaN heterostructure field effect transistors in [181] and [182] by means of gate/drain current measurements and the application of the Hui method [183].
The Analysis Model of AlGaN/GaN HEMTs with Electric Field Modulation Effect
Published in IETE Technical Review, 2020
Luoyun Yang, Baoxing Duan, Ziming Dong, Yandong Wang, Yintang Yang
In the simulation, GaN buffer layer inevitably introduces Si, O impurities or N space, in the metal-organic chemical vapour deposition process. The high background carrier concentration in the GaN buffer layer shows a N-type doping. Therefore, we set up N type doping concentration is 2.0 × 1015 cm−3. In order to get the breakdown curve is consistent with the actual test results, acceptor traps are introduced in the GaN buffer layer. The concentration of the acceptor trap is 2 × 1016 cm−3, located below the conduction band 0.6 eV and carrier capture cross-section area is 1 × 1015 cm2. The breakdown mechanism is avalanche breakdown caused by collision ionization. Usually, the breakdown voltage in the simulation can be determined according to the leakage current value. Therefore, BV of the device is defined as the VDS [27,28] in the cut-off state when IDS reaches 0.1 mA/mm, to avoid permanent degradation of the devices. Next, we verify the model of the four different structure.
Breakdown Mechanisms of Power Semiconductor Devices
Published in IETE Technical Review, 2019
Haijun Guo, Baoxing Duan, Hao Wu, Yintang Yang
Power semiconductor devices are designed to support high voltage within a depletion region formed across either a PN junction or a Schottky junction. The electric field in the depletion region strengthens with increasing applied voltage. Carriers are accelerated in the high electric field region until they acquire sufficient kinetic energy to activate electron–hole pairs, which is a multiplicative phenomenon. This process is referred to as impact ionization, resulting in a significant current flow through the depletion region. It is considered to undergo avalanche breakdown when a rapid increase in the current occurs, accompanied simultaneously by the maximum electric field reaching the critical electric field of the semiconductor material [12].