A Study of Post Annealing Effects in the Repair of High Resistance Failures with Unstable Schottky Barrier Height in 4H-SiC Schottky Barrier Diode

Abstract:

To improve the high resistance and low Breakdown Voltage (BV) of 4H-SiC SBD, the metal annealing process is usually used to to stabilize SBH. We confirmed that post metal annealing after the chip process also stabilizes SBH by the post annealing experiment of applying failure chips (4H-SiC Ti/Al SBD) that have a forward current (I_F) under 1 [A] with high resistance, because of the metal annealing process error. The result of experiments showed that the I_F increment and BV decrement are proportional to the applied temperatures over 450 °C, and the second additional post annealing shows a decrease of I_F and BV. Aluminum and Titanium transformation with post metal annealing made a decrease of SBH, so that the on-resistance is decreased and BV is decreased (in severe cases, the intense post annealing generates Aluminum spiking). From a result of this work, using a suitable post metal annealing, we can improve the I_F of SiC SBD with a high resistance failure from the metal process event.

• Periodical: Materials Science Forum (Volumes 821-823)
• Pages: 588-591
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.821-823.588
• Online since: June 2015
• Authors: Sin Su Kyoung, Eun Sik Jung, Tai Young Kang, Chang Heon Yang, Man Young Sung*
• Keywords: 4H-SiC Schottky Barrier Diode, Post Annealing, Schottky Barrier Height SBH, Transformation

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