Scientists develop new fabrication technology for compound semiconductors

(ATTN: UPDATES with more details, comments from para 4)
By Lee Joon-seung
SEOUL, June 9 (Yonhap) -- South Korean scientists said Tuesday they have
developed a new fabrication technology used to make advanced compound
semiconductors that could help produce more energy efficient mobile devices and
solar cells.

The Hanyang University team led by Oh Jae-eung said it has developed a
"self-aligned dislocation annihilation" method to coat regular silicon-based
semiconductors with other materials like gallium arsenide and indium arsenide.
Such compound computer chips will offer 10 times the "switching" or reaction
speed of normal silicon-based semiconductors and use 90 percent less power,
making them ideal for use in mobile and satellite communication devices.
Compound chips manufactured in this manner can be used to convert sunlight more
efficiently into electrical power and produce improved light emitting diodes
(LEDs).
"The team used the new dislocation annihilation method to cheaply and
successfully 'grow' and attach various compounds over the silicon substrate,"
said Oh, who teaches electrical engineering.
He said that chips produced using so-called defect density phenomena and quantum
dots had a vastly lower defect rate than those being made at present.
"The defect rate was one-hundredth of other manufacturing processes, with the
process having the advantages of easy fabrication and low cost," Oh said.
Existing compound semiconductors are made directly from such artificial materials
like gallium arsenide and indium arsenide. Since such materials are not found
naturally, the cost of production is high. There is a limit on the size of wafers
that can be made with such materials that further hikes up prices.
Foreign companies such as Motorola, AmberWave and Intel have carried out
experiments to cheaply make compound chips with low defect rates, but most have
run into technical difficulties.
The Ministry of Education, Science and Technology, which supported research and
development, said the latest fabrication method could also fuel advances in
nano-complimentary metal oxide semiconductors and integrated optoelectonics
systems.
It added that the new method could promote green information technology industry
and allow local companies, that have largely ignored this field to grab global
market share.
"Compound semiconductors are very expensive and only used sparingly, but if cost
can be brought down demand may shoot up," a government official said.
The technology, meanwhile, has been published in the latest issue of the journal
Nanotechnology and secured one international patent with eight others being
sought in the country and abroad.
yonngong@yna.co.kr
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