CMOS fab compatible GaN goes to 200mm wafers, could reach 300mm

Technology News | November 7, 2017

By eeNews Europe

LEDlighting Power Management Materials & processes

This development follows the company’s demonstration in 2016, of 150mm diameter GaN on QST templates in partnership with Qromis (formerly Quora Technology) who describes its QST templates as a CMOS fab-friendly solution whose key properties (stress, lattice mismatch, thermal stability and shape control) can be engineered independently for the best fit with GaN epitaxial and device layers.

“QST materials layers are integrated together in the conventional semiconductor fab with a simple manufacturing flow”, Qromis mentions on its website, making it possible for large diameter substrates (6-inch, 8-inch, 12-inch or beyond) to support from a few to tens of microns of high-quality GaN epitaxy.

The 200mm diameter HVPE GaN on QST template pictured above consists of 10 microns of HVPE GaN grown on a 5 micron MOCVD GaN on QST wafer provided by Qromis.

X-ray diffraction rocking curve linewidths for the templates fall in the range of 250 and 330 arc-sec for the symmetric {002) and asymmetric {102} XRD peaks, respectively, which is consistent with high structural quality. Low wafer bow (about 50 microns) and smooth surface morphology suggest these materials should support high performance device manufacturing.

Kyma’s newly constructed K200 HVPE tool represents a first for the industry and was designed by Kyma engineers to enable uniform and rapid growth of high quality GaN on a number of different substrates.

“We have successfully transferred the process for making high quality GaN to our K200 HVPE tool. The structural quality of the GaN produced on Qromis’ QST substrate is excellent. We are currently engaging with customers interested in large diameter GaN on QST templates”, said Kyma’s President and CEO Keith Evans in a statement.

Qromis recently began manufacturing 200mm QST substrates and GaN-on-QST wafers using its foundry partner Vanguard International Semiconductor (VIS). VIS is planning to offer GaN power device manufacturing services on 8-inch diameter QST platform in 2018.

Qromis co-founder and CEO Cem Basceri noted that the CMOS fab-friendly 200mm diameter QST substrates and GaN-on-QST wafers enable GaN epitaxy from a few microns to hundreds of microns for GaN power applications ranging from 100V to 1,500V or beyond in lateral, quasi vertical or vertical device forms. The substrates also allow device manufacturing on the same 8-inch or 12-inch diameter platform at Si power device cost, according to Qromis’ CEO.