EPI is the leading supplier of MBE technology which they bought from Varian by way of Intevaac. Pirelli and Lasertron purchased EPI MBE's for laser production because they licensed the IBM 980 nm InGaAs LD production process, which is MBE based. At the time, IBM was perhaps only the second high profile optoelectronics producer to use MBE (in my ignorance, I may be ignoring Bell, HP and a host of other opto pioneers in Japan), and did so only because the MBE approach was a legacy from their research (pre-commercialization) days. The first was Rohm who still manufactures CD lasers by this technique, but also went down this road for legacy reasons. MBE has gained viability in the perception of the community for laser production as a result since IBM (now Uniphase) produces the best high power InGaAs lasers (70% share, as posted recently on this or another thread) and Rohm has profitably produced commodity lasers for years. MBE also has a large share of the high performance transistor market.
Before Rohm and IBM, the joke about MBE as a production technology went that it was the simply the world's most efficient producer of paper. This reflected the fact that MBE is very good for first pass studies and academic environments where the cost of safety (MOCVD uses highly toxic gases) ruled out MOCVD. MBE's have proliferated in academia and MBE proprietors have racked up prolific publication lists whose length far outweigh their worth to science.
For production, MBE is more expensive and lower throughput than MOVCD. Therefore all LEDs, and most other compound semiconductor devices are manufactured by MOCVD. MBE is suitable for high value add devices such as high end laser diodes (>$100 chip) because it has improved process control in the InAlGaAs material system, and produces higher quality material, basically because the crystal is cleaner when grown by this technique.
Basically, if you are producing a Mercedes which requires high performance, you can afford and may choose MBE since your product demands a premium. Nevertheless, most LD suppliers, and all suppliers of lower cost components like LEDs, choose MOCVD for its lower cost of ownership in a production environment where you can amortize safety costs with high throughput. As far as I know, all MBE producers are legacies.
Mr. Gottlieb called MOCVD outdated technology. He couldn't be farther from the truth. In lasers, MOCVD is your first thought, while MBE is an approach you take if you can justify it. For the InAlGaP system which SLIC is pursuing, MBE hasn't demonstrated an advantage over MOVPE in material quality since phosphorus doesn't lend itself to the MBE environment as well as arsenic does.
Leading suppliers of MOCVD technology are Emcore of the US and Aixtron AG of Germany. Other suppliers of MBE are Riber of France and VG (now Fisons, Marie?) of Great Brittain.
With the boom in visible LEDs, both Emcore and Aixtron are doing blow out business. If you want to learn more about this industry, I suggest you subscribe to Compound Semiconductor magazine which Marie Meyer, who contributes occasionally edits. It's a bargain at about $50 for anyone investing in optoelectronics or high speed transistor companies. |
