CLA-2 CO:R:C:M 952000 LTO
District Director
U.S. Customs Service
555 Battery Street
P.O. Box 2450
San Francisco, California 94126
RE: Protest No. 2809-92-100484; KLA Series 5000 Coherence Probe
Metrology System; "optical"; HQ 084646; HQ 088231; 9012; EN
90.31; Add. U.S. Note 3 to Chapter 90; Corning Glass Works
v. U.S.
Dear Sir:
This is in reference to Protest No. 2809-92-100484, dated
March 10, 1992, which concerns the classification of the KLA
Series 5000 Coherence Probe Metrology System (KLA 5000) under the
Harmonized Tariff Schedule of the United States (HTSUS).
FACTS:
The article in question is the KLA 5000, which is an
automated system that performs user-defined metrology
measurements on multilayer integrated product wafers. The KLA
5000 consists of four major subsystems: (1) optics
(interferometer microscope); (2) software; (3) electronic
hardware (computer and hardware); and (4) mechanical system/wafer
loading system (magazine with wafers and robotic arm).
The white light interferometer incorporated into the KLA
5000 contains an imaging lens, a beamsplitter, a microscope
objective, a reference mirror and an illumination source. The
interferometer splits incoherent light into two wave fronts. The
zone where the paths interfere is called the coherence region.
If both paths are equal, an interference signal is generated at a
camera.
As the system scans the wafer's semiconductor substrate, - 2 -
interference is detected when the top of the feature passes
through the coherence region. When the bottom of the surface
passes through the coherence region, interference takes place at
the camera for that area. The system combines the interference
signal from all pixels. Image-processing algorithms determine
the top and bottom widths, the pitch and feature height
information.
The KLA 5000 has two metrology modes, linewidth registration
and overlay. Measurement is performed by collecting both phase
and amplitude information by the Coherent Probe Microscope (CPM),
and then sending this information to the computer. The computer
calculates and reports the dimensions and cross section of the
wafer.
The KLA 5000 was entered under subheading 9031.80.00, HTSUS,
which describes other measuring or checking instruments (parts of
the KLA 5000 were entered under subheading 9031.90.60, HTSUS).
The entry was liquidated under subheading 9031.40.00, HTSUS,
which describes other optical measuring or checking instruments
(the entry of parts of the KLA 5000 was liquidated under
subheading 9031.90.40, HTSUS).
ISSUE:
Whether the KLA 5000 Coherence Probe Metrology System is an
"optical" measuring or checking instrument under the HTSUS.
LAW AND ANALYSIS:
The General Rules of Interpretation (GRI's) to the HTSUS
govern the classification of goods in the tariff schedule. GRI 1
states in pertinent part that "for legal purposes, classification
shall be determined according to the terms of the headings and
any relative section or chapter notes . . . ."
The KLA 5000 is classifiable under Heading 9031, HTSUS,
which provides for "[m]easuring or checking instruments,
appliances and machines, not specified or included elsewhere in
this chapter; . . . parts and accessories thereof." This
determination is not in dispute. However, the subheadings at
issue are as follows:
9031.40.00 Other optical instruments and
appliances
* * * * * * * * * * * * *
9031.80.00 Other instruments, appliances and
machines - 3 -
The protestant argues that the KLA 5000 is not an optical
instrument for the following reasons: (1) the KLA 5000 is
functionally similar to the laser scanning microscope that this
office determined was not an optical microscope in HQ 088231,
dated March 8, 1991; (2) the KLA 5000 does not aid human vision;
(3) the Harmonized Commodity Description and Coding System
Explanatory Notes (EN) to Heading 9031, HTSUS, support the
classification of the KLA 5000 as "non-optical"; and (4) the KLA
5000's optical components perform only a subsidiary role in the
operation of the instrument.
In HQ 088231, dated March 8, 1991, this office classified a
scanning laser microscope under subheading 9012.10.00, HTSUS,
which provides for microscopes, other than optical microscopes.
The protestant claims that the KLA 5000 is functionally similar
to the scanning laser microscope, in that both are used to focus
light and collect data for electronic processing, and, therefore,
should be classified as "non-optical." This ruling, however, is
inapplicable to the case at hand.
In HQ 088231, the issue was whether the microscope in
question was an optical microscope, not whether the article was
an optical measuring or checking instrument. In holding that the
scanning laser microscope was not an optical microscope, we
stated as follows:
The scanning laser microscope under consideration
is neither a compound nor a simple optical
microscope. It does not use microscope objectives
to form and magnify images of the specimen. The
images are formed when the collected data is
processed electronically and displayed on a
monitor. Although the microscope has optical
elements, these elements are used to focus the
laser beam onto the specimen. They are not the
image forming optical elements which are the
principal and most important optical components
of "optical microscopes".
We then stated that the scanning laser microscope's "method
of forming images is much more similar to that of an electron
scanning microscope than an optical microscope," and held that
the microscope was classifiable under subheading 9012.10.00,
HTSUS. We did not hold, nor infer, that the scanning laser
microscope was "non-optical." As such, HQ 088231 is not relevant
to the classification of the KLA 5000.
The protestant claims that the KLA does not aid human
vision, and therefore, cannot be considered an "optical
- 4 -
instrument." This restrictive interpretation limiting the terms
"optical instruments" or "optical appliances" to instruments
which aid human vision is based on outdated notions. Because of
advancements in technology in the field of optics, many apparatus
operate through the use of optical elements.
In HQ 084646, dated September 13, 1989, this office held
"that an instrument is an optical instrument for classification
purposes if the optics are required to process . . . the
information in order to present it in usable form. This
constitutes an aid or an enhancement of human vision." Further,
EN 90.31, pg. 1533, states that subheading 9031.40, HTSUS,
"covers not only instruments and appliances which provide a
direct aid or enhancement to human vision, but also other
instruments and apparatus which function through the use of
optical elements or processes." Thus, the fact that the KLA 5000
does not provide a direct aid or enhancement to human vision does
not take it beyond the scope of subheading 9031.40.00, HTSUS.
The protestant contends that the Explanatory Notes to
Heading 9031, HTSUS, support the classification of the KLA 5000
as "non-optical," and that the optical components of the KLA 5000
perform only a subsidiary role in the operation of the
instrument. Therefore, the protestant claims that the KLA 5000
cannot be classified as an optical instrument. We disagree.
EN 90.31, pg. 1532, lists a number of optical measuring and
checking devices. This list, however, includes interferometers,
which, it states, "are based on the principle of light
interference, and comprise a standard optical flat and lenses
with micrometric cross wires for measuring the interference
bands." As stated above, the KLA 5000 incorporates a white light
interferometer. Thus, the notes actually support the
classification of the KLA 5000 under subheading 9031.40.00,
HTSUS.
Finally, the protestant argues that the optical functions of
the KLA 5000 are subsidiary to the remaining functions of the
instrument, because these functions are not "at least co-equal"
to the instrument's non-optical functions. See Corning Glass
Works v. U.S., 82 Cust. Ct. 249, C.D. 4807 (1979). Additional
U.S. Note 3 to Chapter 90 states that "[f]or the purposes of this
chapter, the terms 'optical appliances' and 'optical instruments'
refer only to those appliances and instruments which incorporate
one or more optical elements, but do not include any appliances
or instruments in which the incorporated optical element or
elements are solely for viewing a scale or for some other
subsidiary purpose."
While the optical components of the KLA 5000 make up only a
- 5 -
small portion of the total value of the system (9.25% of the
total value), they are integral to the basic function of the
apparatus, which is to perform user-defined metrology
measurements on multi-layer integrated product wafers.
Measurement is performed by collecting both phase and amplitude
information by the Coherent Probe Microscope. A computer then
calculates the information sent to it by the optical components
of the KLA 5000.
In Corning Glass Works, the court stated that "[s]ince the
Rota's [a machine for the optical inspection of drug-filled
ampuls] sole purpose is optical inspection, its optical element
is obviously at least coequal in function to the machine's
nonoptical features." Id. at 257-258. The court further stated:
Although . . . an article cannot be classified as an
optical instrument unless the dominant or primary use
of the article lies in the employment of its optical
features, it must be recognized that the optical
element itself need not be the most important or
dominant element of the instrument. As held in Ataka
[U.S. v. Ataka America, Inc., 64 CCPA 60, C.A.D. 1184,
550 F.2d 33 (1977)], "the statutory distinction is
between 'subsidiary' and not 'subsidiary' [and not
whether the optical element is 'subsidiary' or
'dominant']." Id. at 258.
The optical components of the KLA 5000 are not used merely
to obtain a readout or measurement of the results achieved
independently by the nonoptical features of the machine. The
primary function of the KLA 5000 is to perform user-defined
metrology measurements. The optical elements of the KLA 5000
must be employed to perform this function. In fact, the optical
components of the KLA 5000 are what sets the system apart from
other optical measurement systems. In the literature provided by
the protestant, it states:
The use of a white light incoherent source
eliminates the ringing which degrades measurement
integrity on narrow-band microscopes . . . . The
combination of white light interferometer optical
processing and computer extraction of phase and
amplitude information also results in a narrower
point-spread function than that inherent in other
optical measurement techniques. A narrower point-
spread function produces higher resolution for
superior measurement performance.
Clearly, therefore, the function of the optical components
is at least co-equal to that of the KLA 5000's non-optical - 6 -
functions. The optical components are not used to fulfill some
"subsidiary" purpose. Therefore, it is our opinion that the KLA
5000 is classifiable as an optical measuring or checking
instrument. Parts of the KLA 5000 will be classified
accordingly.
HOLDING:
The KLA Series 5000 Coherence Probe Metrology System is
classifiable under subheading 9031.40.00, HTSUS, which provides
for "[m]easuring or checking instruments, appliances and
machines, not specified or included elsewhere in this chapter
. . . parts and accessories thereof . . . [o]ther optical
instruments and appliances." Parts for the KLA 5000 are
classifiable under subheading 9031.90.40, HTSUS. The
corresponding rate of duty for articles of these subheadings is
10% ad valorem.
Accordingly, the protest should be denied in full. A copy
of this decision should be attached to the Customs Form 19 and
provided to the protestant as part of the notice of action on the
protest.
Sincerely,
John Durant, Director