DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
Claims 1-14 are rejected under 35 U.S.C. 103 as being unpatentable over Sukegawa et al (U.S.Pat. 7,826,036) in view of Bruce et al (U.S.Pat. 5,614,990).
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With respect to claims 1, 5, 7-9 and 13-14, Sukegawa discloses an exposure apparatus and corresponding methods comprising: a light source (101), an illumination optical system (104) having a plurality of optical elements (105-107) for changing a wavelength band of light from the light source and configured to illuminate an illuminated surface/a reticle (109) with light of which a wavelength band has been changed by one of the plurality of optical elements; and a control unit (102) configured to control the light source, including wavelength stabilization, discharge control and periodic variation of central wavelength of the exposure light (see abstract). Sukegawa further teaches that the intensity of the exposure light is wavelength-dependent. In particular, Sukegawa divides the wavelength versus intensity distribution into a short-wavelength region and a long wavelength region and calculate integrated intensity values Sws and Swl for the respective wavelength regions. The light source controller (102) controls the source so that the wavelength dependent integrated intensities satisfies a predetermined relationship, thereby reducing nonuniform exposure and maintaining a desired integrated exposure amount during scanning (see Sukegawa, figures 4-6 and the corresponding description). Furthermore, Sukegawa discloses a photosensor (107) that detects the intensity of the exposure light, with the sensor output being converted to exposure energy and communicated to the controller (102). Sukegawa therefore recognizes that different wavelength conditions can produce different illumination-intensity distributions and that the light source must be controlled accordingly. Sukegawa does not expressly disclose its wavelength-dependent control quantities as correction values representing a relationship between a change in illuminance and a change in input power to the light source to maintain constant illuminance on the illuminated surface, as recited in the claims. Bruce teaches an exposure apparatus having a light source, an optical system, an imaging plane corresponding to an illuminated surface, an intensity measurement array (CCD array) and a computer control system. Bruce measures the illumination-intensity distribution at the imaging plane and adjusts the intensities of individual illumination sources based on the measured result to obtain a desired illumination distribution. Bruce’s control process includes measuring intensity, determining an average or target intensity, and increasing or decreasing illumination intensity depending upon the measured deviation (see abstract, and figures 2, 4 and 5). In short, Bruce teaches controlling input power or source intensity based on the relationship between a change in source input and the resulting change in measured illuminance, so as to obtain and maintain a desired illuminance at an illuminated surface. In view of such teachings, it would have been obvious to one having ordinary skill in the art before the effective filling date of the claimed invention to combine the teachings of Bruce and Sukegawa to come up with the claims invention as recited in the claims. It would have been obvious to a skilled artisan to incorporate Bruce’s measurement based source-power correction in to the wavelength-varying exposure apparatus of Sukegawa. Sukegawa expressly recognizes that the delivered light intensity varies as a function of wavelength and spectral position. Bruce teaches the predictable solution of measuring the resulting illumination and increasing or decreasing source intensity to maintain a desired illumination level. It would have been obvious to determine and use a respective correction value for each wavelength-changing optical element or spectral condition when controlling the light-source input power. Doing so would compensate for the different optical transmission responses and predictably maintain substantially constant illuminance when the wavelength-changing optical condition is changed.
As to claim 2, it would having been obvious to present the experimentally determined relationship between source input power and illuminance as an approximation coefficient, such as a slope or gain coefficient, because a coefficient is a conventional and predictable representation of a measured input-output relationship and permits the controller to calculate the amount of source-power adjustment efficiently.
As to claim 3, it would have been obvious to perform Bruce’s illumination measurement and source-intensity variation separately for each wavelength-changing optical condition of Sukegawa to obtain the correction value appropriate to each optical element or spectral condition because Sukegawa recognizes that the intensity response differs depending on wavelength.
As to claim 4, it would have been obvious to derive an approximation formula from two or more such measurement points because using two or measured data points to obtain a linear or other fitted approximation of an input-output relationship was a well-known and predictable calibration technique. Such a formula would allow the controller to calculate the source-power correction required to reach the target illuminance.
As to claim 6, Sukegawa teaches that the wavelength-selection arrangement is disposed in the exposure light source and illumination system and includes wavelength-selecting optical components, including a diffraction grating and prism, whose operation controls the wavelength characteristics of the exposure light. Sukegawa further teaches controlling the wavelength condition according to the desired scanning-exposure operation. It would have been obvious to configure the controller of Sukegawa to select or switch among wavelength-changing optical elements or operating states according to a predetermined exposure condition, such as a desired wavelength ranges, exposure mode, resist sensitivity, numerical aperture, focus range or required depth of focus for the purpose of obtaining a desired exposure amount.
As to claim 10, Bruce teaches comparing measured illumination with a desired or average illumination and increasing or decreasing illumination-source intensity depending on the difference. Thus, it would have been obvious to calculate the power-adjustment amount based on both the correction value representing the response of illuminance to source input power and the difference between target illuminance and current illuminance, because multiplying ore otherwise applying a calibrated input-output correction value to the measured illumination error is a conventional feedback-control technique that directly determines the source-power adjustment needed to reduce the error.
As to claim 11, Sukegawa teaches mathematically comparing quantities associated with different wavelength ranges and using their values in controlling the light source (see equation 1). It would have been obvious to one having ordinary skill in the art to utilize the controller of Sukegawa to calculate a ratio between a correction value for one wavelength band and a correction value for a first wavelength band. A ratio provides a conventional normalized comparison of the relative source-power responses of the two optical conditions and allows the correction for one condition to be derived from or compared with the correction for another.
As to claim 12, Sukegawa’s controller must have a storage unit to function as intended.
Prior Art Made of Record
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
Yamaguchi (U.S.Pat. 12,510,464 B2); Pauls et al (U.S.Pat.12,174,546 B2); Soer et al (U.S.Pat. 9,726,989 B2) disclose exposure devices and have been cited for technical background.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to HUNG HENRY NGUYEN whose telephone number is (571)272-2124. The examiner can normally be reached Monday-Friday 7:00AM-4:30PM.
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HUNG HENRY NGUYEN
Primary Examiner
Art Unit 2882
Hvn
7/21/26
/HUNG V NGUYEN/Primary Examiner, Art Unit 2882
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