Technology Transfer SSC Pacific
Improved Method for Fabricating Trench Structures

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Provides an improved method for fabricating trench structures using a CF4, HBr, and CL2 combination etching process.

The U.S. Navy seeks to commercialize U.S. Patent 6,709,976 (Method for improving reliability in trench structures).


Trench structures are commonly used for controlling high voltages and currents within integrated circuit devices. Current manufacturing  practices use plasma or reactive ion etching to form trenches onto various substrates (e.g. silicon). These processes may result in inconsistencies in trench wall development, leading to irregularities in the deposition of  the insulating layer and possible thinning and dielectric breakdown at high voltages.

The Technology

SSC Pacific has developed an improved method of fabricating trench structures through a combination of tetrafluoromethane (CF4), hydrogen bromide (HBr), and chlorine (CL2) etching. Using predetermined flow rates, radio frequencies, pressure, magnetic fields, and duration results in trenches approximately 2 microns wide by 2 microns deep. These rounded trenches reduce the electrical fields that cause insulator breakdown, providing a more efficient and reliable trench design for various semiconductor applications.

Key Benefits

  • Reduces insulator inefficiencies and dielectric breakdown
  • Greater power density
  • Easily integrated into current trench manufacturing pathways or included as part of a larger fabrication process
  • Development Status

  • U.S. Patent 6,709,976 (Method for improving reliability in trench structures)
  • DoD 5000 Series Technical Readiness Level 3: Analytical and experimental critical function and/or characteristic proof of concept
  • Method tested and achieved in a lab setting
  • For more information on technology transfer, please contact us at (619) 553–5118 or email  
    SD 951. April 2011. SSC Pacific, San Diego, CA 921525001. Approved for public release; distribution is unlimited.

    SSC Pacific
    Updated: 11/7/2011 10:41 AM EST   Published