GaN-Based PCSS with High Breakdown Fields

Electronics

Nicholas Wilson¹  Sergey Nikishin¹  Andreas Neuber¹  Vladimir Kuryatkov¹  Matthew Gaddy¹  Richard Ness² 

[1] Department of Electrical and Computer Engineering, Texas Tech University, Lubbock, TX 79409, USA;NessEngineering Inc., San Diego, CA 92196, USA;

关键词: PCSS;    GaN;    high voltage switch;   

DOI  :  10.3390/electronics10131600

来源: DOAJ

【 摘 要 】

The suitability of GaN PCSSs (photoconductive semiconductor switches) as high voltage switches (>50 kV) was studied using a variety of commercially available semi-insulating GaN wafers as the base material. Analysis revealed that the wafers’ physical properties were noticeably diverse, mainly depending on the producer. High Voltage PCSSs were fabricated in both vertical and lateral geometry with various contacts, ohmic (Ti/Al/Ni/Au or Ni/Au), with and without a conductive n-GaN or p-type layer grown by metal-organic chemical vapor deposition. Inductively coupled plasma (ICP) reactive ion etching (RIE) was used to form a mesa structure to reduce field enhancements allowing for a higher field to be applied before electrical breakdown. The length of the active region was also varied from a 3 mm gap spacing to a 600 µm gap spacing. The shorter gap spacing supports higher electric fields since the number of macro defects within the device’s active region is reduced. Such defects are common in hydride vapor phase epitaxy grown samples and are likely one of the chief causes for electrical breakdown at field levels below the bulk breakdown field of GaN. Finally, the switching behavior of PCSS devices was tested using a pulsed, high voltage testbed and triggered by an Nd:YAG laser. The best GaN PCSS fabricated using a 600 µm gap spacing, and a mesa structure demonstrated a breakdown field strength as high as ~260 kV/cm.

【 授权许可】

Unknown