CLA-2 CO:R:C:F 957293 ALS
Mr. Richard C. King
Attorney at Law
Fitch, King and Caffentzis
116 John Street
New York, NY 10038
RE: Carbon Doped Gallium Arsenide Wafers
Dear Mr. King:
This is in reference to your inquiry regarding the subject
wafers on behalf of Marubeni America, Inc.
FACTS:
The subject merchandise consists of highly-resistive carbon-
doped gallium arsenide (GaAs) wafers. The wafers are produced
from compound crystal ingots grown by the Liquid Encapsulated
Czochralski (LEC) method. The carbon doping concentration is
controlled by degassing impurities present in the raw material
(including contaminated carbon), and then introducing controlled
carbon concentration through the addition of purified carbon
monoxide gas (CO), as the crystal is pulled. The purpose of this
doping procedure is to alter the electrical characteristics of
the wafers, their conductivity and their resistivity. They are
used in electronics.
ISSUE:
What is the classification of the subject wafers?
LAW AND ANALYSIS:
Classification of merchandise under the Harmonized Tariff
Schedule of the United States Annotated (HTSUSA) is governed by
- 2 -
the General Rules of Interpretation (GRI's) taken in order.
GRI 1 provides that the classification is determined first in
accordance with the terms of the headings and any relative
section and chapter notes. If GRI 1 fails to classify the goods
and if the headings and legal notes do no otherwise require, the
remaining GRI's are applied, taken in order.
Counsel has suggested that the subject wafers are properly
classified in subheading 3818.00.0010, HTSUSA, as gallium
arsenide wafers, doped. Customs, however, has historically
classified such wafers under subheading 2851.00.0000, HTSUSA, as
other products of the chemical industry, for wafers under 2.5
grams, or under subheading 3823.90.1900, HTSUSA, for wafers not
less that 2.5 grams. Our rational for doing so has been that all
gallium wafers contain carbon and that such carbon is not in the
proportion required in Explanatory Note 38.18(2) to the
Harmonized System (EN), which represents the view of the
international classification experts.
Counsel notes that carbon doping concentration is controlled
by degassing impurities present in the raw material (including
contaminated carbon), and then introducing controlled carbon
concentration though the addition of purified carbon monoxide gas
(CO), as the crystal is pulled. The process is noted to be
analogous to the process used in the production of silicon doped
boat grown GaAs wafers. Counsel has submitted SEMI M9-90,
Specifications for Polished Monocrystalline Gallium Arsenide
Slices, of the Semiconductor Equipment and Materials
International (SEMI) and draft document number 2048 in support of
its position.
In analyzing these documents we noted that they referred to
carbon as a dopant. We, however, found no basis presented
therein for such conclusion. That document did not seem to
confirm that carbon was added to gallium arsenide wafers in order
to give the material specific electrical properties, i.e.,
increased its resistivity. However, three important technical
sources, ASTM Handbook of Standards, the Encyclopedia of Chemical
Technology, Kirk, Othmer, and the Modern Dictionary of
Electronics, 6th, 1990, do not refer to carbon as a dopant. In
light of this and since the addition of carbon to the gallium
arsenide wafers only increases the carbon in the crystals but
does not introduce the carbon, a question has existed as to
whether it could be concluded that the carbon was introduced to
significantly alter the crystals conductivity. Accordingly, we
had tentatively concluded that carbon was not an industry
recognized dopant and that the subject gallium arsenide wafers
were not doped.
- 3 -
Subsequent thereto counsel submitted certain previously
unavailable technical data on Hitachi III-V Semiconductors it
obtained from the manufacturer of the gallium arsenide wafers
(Hitachi Cable, Ltd.). That technical data confirms in its
specification of AU grade carbon-doped wafers that the wafers,
which are available in several sizes, are carbon-doped and that
the resistivity of each different type of wafer is dependant upon
the concentration of carbon. The data confirms that such doping
is accomplished by special carbon doping manufacturing equipment
which adds carbon during the crystal seeding and growth cycles.
Accordingly, we have concluded that the gallium arsenide wafers
under consideration are doped for use in electronics.
HOLDING:
Carbon-doped gallium arsenide wafers in which carbon is
added during the crystal seeding and growth cycles to control the
conductivity or resistivity of the wafers, are classifiable in
subheading 3818.00.0010, HTSUSA, Gallium arsenide wafers, doped,
for use in electronics. Such wafers are subject to a free rate
of duty.
Sincerely,
John Durant, Director
Commercial Rulings Division