HQ 952000

January 28, 1993

CLA-2 CO:R:C:M 952000 LTO

CATEGORY: Classification

TARIFF NO.: 9031.40.00; 9031.90.40

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

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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