Apparently, Aixtron has been working with MOT and IQE on the heterowafers.
>> COMPOUND SEMICONDUCTORS EXTENDING SCOPE OF APPLICATIONS:
HEMT ON SILICON WAFERS FABRICATED WITH AIXTRON´S ADVANCED HETEROWAFERâ TECHNOLOGY
Aachen, September 6th, 2001 - AIXTRON AG is proud to announce the successful development of III-V Compound Semiconductor Transistor Material Technology on Silicon Wafers. In particular High Electron Mobility Transistors (HEMT) have been built from III-V on Silicon Wafers produced with this new technology. This great accomplishment, based on a cooperation between device researchers, as users, and AIXTRON, is a result of 5 years persistent materials technology development. The key enabling step is the achievement to produce III-V heterostructure epitaxial material on standard Silicon Wafers in a commercial III-V LP-MOCVD system, which includes additional proprietary features for the HeteroWaferâ technology. AIXTRON owns a substantial number of patents and IP rights protecting the key underlying MOCVD technology, and has further applied for additional patents in its field of business for the particular HeteroWaferâ technology resulting from this development at AIXTRON (see AIXTRON annual report 2000).
Using Silicon Wafers or alternative substrates for production of Compound Semiconductor devices will strongly contribute to cost reductions and scaling of Compound Semiconductor manufacturing technologies in particular for electronic devices.
The initial developments started already about 15 years ago by investigations of GaAs and related III-V material synthesis routes by means of MOCVD. Core know how was accumulated over the years, already resulting in 1992 in the design of the worlds largest MOCVD reactor, the AIX 3000, a true multiwafer 12" (300mm) technology, with a capacity of 3 of these large 12" Silicon wafers. Detailed process development at this large scale continued, developing base processes for the required variety of III-V materials, from GaAs, AlGaAs, to GaInP, AlGaInP, and reaching into the InP material system. In the continuing years first MOCVD epitaxial processes for these III-V materials have been demonstrated on the multiwafer 8" scale, being today available on a manufacturing level since a few years already.
Advanced III-V MOCVD synthesis routes have further been developed on Silicon, Sapphire, SiC or Germanium Wafers in order to foster the understanding of the critical step to deposit Compound Semiconductor Material onto wafers of different nature, thermal behavior or conductivity. This contributed to the successful development of AlGaN/InGaN/GaN production on Sapphire Wafers which is already today in high volume production for blue, green and white LED applications.
This proprietary CVD technology has resulted further in large tool installations for the Silicon-Germanium technology on Silicon Wafers, taking advantage of AIXTRON´s unrivaled Planetary Reactorâ. This SiGe CVD tool has a capacity of 3 of the 8" silicon wafers at a time, thus providing 3 times the capacity and throughput of other commercial SiGe CVD tools.
A similar SiGe tool, the SiGe Tricentâ, had been launched earlier this year as 200mm/300mm bridge tool, and will be introduced into manufacturing at IQE Silicon Compounds as announced in June of this year. The same tool is also available for STO (Strontium Titanium Oxide) and other multicomponent oxides, and can be directly integrated with the SiGe Tricentâ module
onto the same Cluster Platform. Both, SiGe Tricentâ and the 3x8" Planetary Reactorâ, are also covering the “strained Silicon” approach.
Today, another critical milestone in this long chain of development steps is announced: AlGaN/GaN HEMT devices fabricated onto Silicon Wafers using this advanced AIXTRON HeteroWaferâ epitaxy technology have been demonstrated by users. These HEMTs are known to have great perspectives for high-frequency, -power and –temperature applications. The 0.3 µm gate devices developed by the user have undergone rigid qualification. They exhibit a saturation current of 0.82 A/mm, excellent pinch off, and peak intrinsic transconductance of 110 mS/mm for doped structures. The advantage of these materials is the enhanced thermal durability for high-power electronics, allowing prototype operation at 16 W/mm static heat dissipation, without degradation of performance. AIXTRON´s HeteroWaferâ epitaxy technology is made available on a free-of-charge User License base along with all new MOCVD equipment purchases dedicated to such material systems. |
