News Article

BEEM Reveals Electrical Properties Of Dislocations And Nanopipes (Research Review)

It has been shown that SiC power devices fabricated on micropipe-free SiC wafers exhibit a dramatic improvement in electrical properties compared with devices fabricated on wafers containing micropipe defects; see P G Neudeck and J A Powell in Electron Device Letters 1994, 15, p63. Micropipe-related defects cause pre-avalanche breakdown in SiC power devices by facilitating electrical discharge through the hollow core of nanopipes under high electric field operation. This mechanism contributes to large leakage currents. A team led by C V Reddy and V Narayanamurti at Harvard University have employed ballistic electron-emission microscopy (BEEM) to image dislocations and nanopipes in SiC that have so far proved difficult to detect with either SEM and AFM techniques (Journal of Applied Physics 2001, 89, p5797). Topographic AFM images taken from 300 300 nm areas on two different SiC samples reveal different kinds of defects (see ). Image (a) shows a defect with an associated deep trench that is commonly observed all over the SiC matrix. A nanopipe-related defect is shown in the image labeled (b), and the area is enlarged in the inset. BEEM spectroscopy performed on the defect and the adjacent area revealed that large electric currents are concentrated around the nanopipe/dislocation sites. The authors note that the nanopipe may not actually have a hollow core to facilitate the electrical discharge. However, they conclude that since the defect is highly conducting, it is responsible for the large leakage currents observed in SiC power devices.
CS International to return to Brussels – bigger and better than ever!


The leading global compound semiconductor conference and exhibition will once again bring together key players from across the value chain for two-days of strategic technical sessions, dynamic talks and unrivalled networking opportunities.


Join us face-to-face between 28th – 29th June 2022

  • View the agenda.
  • 3 for the price of 1. Register your place and gain complementary access to TWO FURTHER industry leading conferences: PIC International and SSI International.
  • Email info@csinternational.net  or call +44 (0)24 7671 8970 for more details.

*90% of exhibition space has gone - book your booth before it’s too late!

Register


×
Search the news archive

To close this popup you can press escape or click the close icon.
×
Logo
×
Register - Step 1

You may choose to subscribe to the Compound Semiconductor Magazine, the Compound Semiconductor Newsletter, or both. You may also request additional information if required, before submitting your application.


Please subscribe me to:

 

You chose the industry type of "Other"

Please enter the industry that you work in:
Please enter the industry that you work in:
 
Live Event