TSMC's LED Business Likely to Benefit From Bridgelux's Ga-on-Si Technology

Taipei, Aug. 17, 2011 (CENS)--TSMC Solid State Lighting Ltd., an LED subsidiary wholly owned by foundry giant Taiwan Semiconductor Manufacturing Co. (TSMC), is likely to acquire the GaN-on-Silicon technology recently launched by Bridgelux Inc. of the Untied States, in which TSMC-held VTAF has stakes.

Bridgelux Chief Executive Officer (CEO) Bill Watkins pointed out that the company would work with a well-known chipmaker on LED manufacturing using the latest technology to pare down cost and increase profit. Based on the statement, Taiwan's press media associated the unspecified chipmaker with TSMC.

According to Bridgelux, the new technology allows LED makers to produce devices that outperform silicon carbine-based LEDs and sapphire-based LEDs and are less expensive relative to the latter two technologies.

Bridgelux executives noted that growing GaN on larger, low-cost silicon wafers that are compatible with modern semiconductor manufacturing can deliver a 75% improvement in cost over current approaches. Cool white LEDs built with the technology showed efficiencies as high as 160 Lm/W at a CCT of 4350K. Warm white LEDs constructed from the GaN on Si chips delivered 125 Lm/W at a color temperature of 2940K and CRI of 80.

Steve Lester, Bridgelux chief technology officer, claimed that the performance levels that the company announced with the technology are the highest Lm/W values yet published for GaN-on-Si and rival the best commercial LEDs grown on sapphire or silicon carbine.

The technology uses a proprietary buffer layer technology, which grows crack-free GaN layers on 200mm silicon wafers without bowing at room temperature. The technology fixes the larger thermal expansion coefficient of GaN than that of silicon. This mismatch can cause the epitaxial films to crack, or the wafers to bow, either during epitaxial growth or at room temperature.

Watkins pointed out that this key innovation is a game-changer for the industry as it delivers dramatic reductions in the up-front capital investment required for solid state lighting and thereby significantly increasing the rate of market adoption.