Technology allows large wafer production

The AIX 2800G4 HT reactor which is able to handle 50 x 50mm sapphire wafers along with 50.8mm wafers.

Aixtron and CrystalQ have presented initial test results from a 150mm C-plane GaN-on-sapphire wafer.

One way to increase the throughput of white LED manufacturing, while meeting the cost and yield targets, is to increase the wafer size.

Currently, the standard wafer size in the industry is 50.8mm and a limited group of high-end LED manufacturers have switched to processing 76.2 or 101.6mm wafers.

The feasibility of higher throughput requires up-scaling of existing technologies to 150mm wafers and an attractive return on investment.

To achieve these conditions, a fabrication technology for 150mm C-plane sapphire wafers needed to be developed that would ensure identical layer deposition results as standard sizes.

A high yield for LED chip-manufacturers needed to be ensured.

Therefore Aixtron has introduced a flexible mass-production deposition equipment, the AIX 2800G4 HT reactor which is able to handle 150 x 150mm sapphire wafers along with 50.8mm wafers, while ensuring optimum uniformity of the epitaxy-layer growth.

CrystalQ has developed enhancements of the current, proprietary CMP-polishing process.

Innovative fabrication tool design resulted in efficient handling and in controllability of roughness and flatness parameters of the 150mm C-plane sapphire substrates.

Efforts has been put into the reduction of the edge-exclusion zone to optimise the number of LED chips per wafer.

The standard deviation of the wavelength on the photoluminescence map was 2.48nm (0.55%) without edge exclusion.

This development project also has resulted in implementing recycling processes for 150mm sapphire wafers, which reduces operational costs for white LED manufacturers.

Back to top