+44 (0)24 7671 8970
More publications     •     Advertise with us     •     Contact us
News Article

Eta Research announces GaN wafers for laser diode makers


Eta Research has announced free-standing GaN wafers for laser diode manufacturers at sizes of 2 inches and 4 inches, with conductivity available in either Si-doped n-type or C-doped semi-insulating.

Eta says its GaN wafers have been engineered to meet the requirements for laser diode manufacturers in a number of ways.

Orientation flat alignment

The wafer orientation flat must be closely aligned to the GaN m-plane since lasers may be manufactured by cleaving on the crystallographic plane. Eta has developed the process to achieve 0.0 ± 0.1 degrees alignment of the orientation flat to the crystallographic plane.

Dislocation density

Typical XRD rocking curve FWHM for both (002) and (102) are in the range of 40 to 50 arcsec. The dislocation density was measured by both CL and etch pit methods, and was found to be in the range of 5E5 to 9E5 /cm2.


Eta’s standard offcut is 0.5 degrees toward the m-direction and 0.0 inches toward the a-direction at the center point of the wafer. The center point offcut can be customized in the range of 0.2 degrees to 0.6 degrees.

Lattice radius and offcut variation

The lattice radius specification is > 10 m, and typical values range from 20 m to 60 m with the shape as concave. The offcut variation can be calculated from the lattice radius. However, since there is a small concave wafer bow, the actual offcut variation is less than would be calculated from the lattice radius. The offcut was measure by XRD with x-ray reflection alignment to the real wafer surface. The offcut variation over a 4 inches wafer was measured as 0.06 degrees for both the m-direction offcut and a-direction offcut. For example, the m-direction offcut was 0.47 degrees on one edge and 0.53 degrees on the other edge over the entire 100 mm of the wafer.

Frontside Ga-face polish

The Ga-face is polished to an average roughness of 0.15 nm measured by a 10 µm x 10 µm AFM scan. The wafer is cleaned in a special process to remove any contamination from the polishing procedure. Removal of trace metal impurities from the surface was confirmed by TXRF.

Backside N-face finish

The backside finish is available in either polished or etched. The average roughness of the backside surface measured by 3D profiler over 239 µm x 318 µm is 1 nm for polished and 1 µm for etched.

Search the news archive

To close this popup you can press escape or click the close icon.
  • 1st January 1970
  • 1st January 1970
  • 1st January 1970
  • 1st January 1970
  • View all news 22645 more articles
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: