Single event burnout of high-power diodes

Single-event burnout (SEB) is a catastrophic failure mechanism in power diodes that is initiated by the passage of a heavy ion through a diode in a current-blocking state. In this work, the physical mechanism responsible for device failure during SEB is investigated using transient, coupled electro-thermal, device simulations. For the first time, the effects of a thermal feedback mechanism have been examined and deemed crucial to predicting possible failure in power diodes. Results indicate that device failure is predicted for large blocking voltage near breakdown with a linear energy transfer (LET) of 30MeV/mg/cm2 only when thermal effects are included. However, without inclusion of the thermal model, no device failure is predicted. These results correspond to experimental observations better than any previous work.

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Time evolution of the two-dimensional expansion velocity distributions of the cathode plasma in pulsed high-power diodes

Laser and Particle Beams ◽

10.1017/s0263034612001127 ◽

2013 ◽

Vol 31 (1) ◽

pp. 129-134 ◽

Cited By ~ 15

Author(s):

Jie Yang ◽

Ting Shu ◽

Yuwei Fan

Keyword(s):

High Power ◽

Cathode Surface ◽

Transverse Velocity ◽

Longitudinal Velocity ◽

Expansion Velocity ◽

Two Dimensional ◽

Plasma Expansion ◽

Cathode Plasma ◽

Power Diodes ◽

Diode Current

AbstractA combination of electrical and optical diagnostics has been used to investigate the time evolution of the two-dimensional expansion velocity distributions of the cathode plasma in pulsed high-power diodes. The perveance model based on the Child-Langmuir law was used to calculate the expansion velocity of the diode plasmas from voltage and current profiles. Additionally, a four-channel high speed framing camera was used to observe the formation and subsequent movement of the cathode plasma. More accurate and valuable information about the dynamics of the cathode plasma was also acquired by utilizing the digital image processing methods. Results from the experiments and theoretical analysis were compared. In this paper, the experiments have been performed using a high-voltage pulse generator with 200 kV output voltage and 110 ns pulse duration. Current densities up to 440 A/cm2were produced. The observation of the cathode plasma expansion in transverse direction indicated that the diode current was cathode-limited in the current rising stage (the first 60 ns of the current pulse). The perveance model should be modified taking in account the time dependent expanding plasma surface (i.e., not the whole cathode surface) for this period. The velocity in the direction parallel to the cathode surface (transverse velocity) was much larger than that in the direction perpendicular to the cathode surface (longitudinal velocity), and further, it dropped from 90 cm/μs to nearly 20 cm/μs rapidly. It was shown that, during the current flattop stage, the plasma filled out all the surface of cathode and the diode current was space-charge-limited. The values of the transverse velocity and longitudinal velocity were nearly the same and decreased relatively slowly. The satisfactory coincidence of experimental and calculated (both were in the range of 6–8 cm/μs) values of the cathode plasma expansion velocities was obtained.

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