editor's blog
Subscribe Now

Engineering GaN Wafers

We talked before about wide bandgap materials such as GaN and SiC, but how are the base wafers for those materials created? Full wafers of expensive material would be, well, expensive. But if you grow or somehow affix the material on a base material of some other sort, you run the risk of having thermal issues at the boundary (at the very least).

Sumitomo and Soitec announced a joint approach recently that provides a GaN layer on top of some other substrate. The key is that this substrate is thermally matched to GaN. Of course, when I inquired as to the nature of the material, I found it was this mystery material that seems to be common to a huge number of projects: the material is called “proprietary.”

The method of creating the GaN on top of this takes a page from how Soitec creates SOI base wafers, with their SmartCut process. If you haven’t heard about it before, it’s interesting. The concept is that, in this case, Sumitomo sends them a pure GaN wafer. Soitec provides the base and then slices off a thin layer of GaN and affixes it to the base wafer. So one GaN wafer gets sliced many many times and ends up serving a large number of actual used wafers, stretching the GaN material as far as it will go.

So you might wonder, how do you slice off such a thin layer? Here’s what they do: first they implant hydrogen into the top of the GaN wafer down to the thickness of the layer they want to cut off. They then turn this wafer upside down and affix it to the base wafer, so now you have two wafers bonded together face-to-face.

They then use heat to create bubbles at the layer where the hydrogen is; this causes cracking along that seam, and the GaN bulk wafer comes off, leaving just the thin layer attached to the new base material. A little spit and polish and you’re good to go.

They had done this with 2” wafers before; their recent announcement demonstrates scaling to 4” and 6” wafers. You can find more in their release.

Leave a Reply

featured blogs
Mar 18, 2024
If you've already seen Vivarium, or if you watch it as a result of reading this blog, I'd love to hear what you think about it....
Mar 18, 2024
Innovation in the AI and supercomputing domains is proceeding at a rapid pace, with each new advancement heralding a future more tightly interwoven with the threads of intelligence and computation. Cadence, with the release of its Millennium Platform, co-optimized with NVIDIA...
Mar 18, 2024
Cloud-based EDA tools are critical to accelerating AI chip design and verification; see how NeuReality leveraged cloud-based chip emulation for their 7NR1 NAPU.The post NeuReality Accelerates 7nm AI Chip Tape-Out with Cloud-Based Emulation appeared first on Chip Design....

featured video

We are Altera. We are for the innovators.

Sponsored by Intel

Today we embark on an exciting journey as we transition to Altera, an Intel Company. In a world of endless opportunities and challenges, we are here to provide the flexibility needed by our ecosystem of customers and partners to pioneer and accelerate innovation. As we leap into the future, we are committed to providing easy-to-design and deploy leadership programmable solutions to innovators to unlock extraordinary possibilities for everyone on the planet.

To learn more about Altera visit: http://intel.com/altera

featured paper

Reduce 3D IC design complexity with early package assembly verification

Sponsored by Siemens Digital Industries Software

Uncover the unique challenges, along with the latest Calibre verification solutions, for 3D IC design in this new technical paper. As 2.5D and 3D ICs redefine the possibilities of semiconductor design, discover how Siemens is leading the way in verifying complex multi-dimensional systems, while shifting verification left to do so earlier in the design process.

Click here to read more

featured chalk talk

Digi XBee 3 Global Cellular Solutions
Sponsored by Mouser Electronics and Digi
Adding cellular capabilities to your next design can be a complicated, time consuming process. In this episode of Chalk Talk, Amelia Dalton and Alec Jahnke from Digi chat about how Digi XBee Global Cellular Solutions can help you navigate the complexities of adding cellular connectivity to your next design. They investigate how the Digi XBee software can help you monitor and manage your connected devices and how the Digi Xbee 3 cellular ecosystem can help future proof your next design.
Nov 6, 2023
17,644 views