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 .
DETAILED ACTION
Amendment filed on 4/30/26 has been entered.
Response to Arguments
Applicant’s arguments with regard to the amendment have been fully considered but they are moot because the arguments do not apply to any of the references being used in the current rejection.
Claim Objections
Claim 15 is objected to because of the following informalities: in the line 9, the phrase “on etch stop layer” should be corrected “on the etch stop layer”.
Appropriate correction is required.
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 of this title, 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, 3-7, 9, 11, 13-18 and 20 are rejected under AIA 35 U.S.C. 103 as being unpatentable Mouli (US 20060006485) in view of Maeda (US 20130134540).
Regarding claim 1, Fig 2 (a detail portion view of Fig 7), Fig 4A (a detail portion view of Fig 7) and Fig 7 of Mouli disclose An image sensor comprising:
a sensor substrate 1 including a plurality of first pixels ([0034]/[0035]/[0062]: Fig 7 shows only a portion of image sensor pixel array and includes pixel cells 10, the array is similar to array 100 in Fig 1A. And the pixel cells 10 receive different wavelengths of light, such as red, green, blue. Thus, the red pixels of the array is a plurality of first pixels) and
a plurality of second pixels for sensing light of a second wavelength band that is different from the first wavelength band (the green pixels of the array is a plurality of second pixels);
a color filter layer 30 [0004] on the sensor substrate, the color filter layer including a plurality of color filters [0062];
an encapsulation layer 205 arranged on the color filter layer (Fig. 7, [0038]: Mouli teaches that layer 205 may include SiO₂ and is disposed beneath the nano-photonic structures. Because claim 1 merely recites an “encapsulation layer” without specifying any required structural, material, or functional limitation beyond positional arrangement within the optical stack, layer 205 reasonably corresponds to the claimed encapsulation layer under the broadest reasonable interpretation);
and a nano-photonic lens array 260′ arranged over the encapsulation layer, the nano-photonic lens array including a plurality of nano-structures 262 arranged to condense incident light onto the plurality of first pixels and the plurality of second pixels ([0049], [0059]).
But Mouli does not expressly disclose a planarization layer arranged on the color filter layer, wherein the planarization layer is arranged between the color filter layer and the encapsulation layer.
However, Maeda discloses a planarization layer 21 disposed over color filter layer 20 and beneath encapsulation/stress-relaxation layer 22 (Fig. 3, [0051]). Maeda further teaches that planarization layer 21 planarizes uneven topography generated by the underlying color filter structures for subsequent formation of overlying optical structures.
Thus, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to incorporate Maeda’s planarization layer arrangement into Mouli’s image sensor structure such that the planarization layer is disposed between the color filter layer and encapsulation layer in order to improve surface planarization, optical uniformity, stress relaxation, and manufacturability of the nano-photonic lens array structure.
Regarding claim 3, Mouli in view of Maeda discloses the image sensor substantially as recited in claim 1. Maeda further discloses that the planarization layer 21 includes an organic polymer material. Specifically, Maeda discloses that the planarization layer is preferably formed of transparent and heat-resistant resin materials, including an acrylic thermosetting resin material, a styrene resin material, and an epoxy resin material [0051]. The disclosed acrylic resin material, styrene resin material, and epoxy resin material are organic polymer materials within the ordinary meaning of the term.
Regarding claim 4, Mouli in view of Maeda discloses the image sensor substantially as recited in claim 3. Maeda further discloses that the planarization layer may include acrylic thermosetting resin material, styrene resin material, and epoxy resin material [0051]. The disclosed epoxy resin material corresponds to the claimed epoxy resin, while the disclosed acrylic resin material reasonably corresponds to polyacrylate and/or polymethyl methacrylate materials, which are well-known acrylic polymer materials conventionally used as transparent planarization resins in semiconductor and image sensor fabrication.
Thus, it would have been obvious to one of ordinary skill in the art at the time the invention was made to select known organic polymer materials, including epoxy resin, polyacrylate, and polymethyl methacrylate, for the planarization layer because such materials were well known in the art for providing transparency, planarization capability, thermal stability, and process compatibility in image sensor fabrication. The selection of one known polymer material from a finite number of known suitable planarization materials would have constituted a routine design choice yielding predictable results.
Regarding claim 5, Mouli in view of Maeda discloses the image sensor substantially as recited in claim 1. Mouli discloses the encapsulation layer includes an inorganic material including at least one from SiO2 [0038], SiN, and SiON.
Regarding claim 6, Mouli in view of Maeda discloses the image sensor substantially as recited in claim 1.
Maeda further discloses that the planarization layer 21 may be formed of acrylic resin having a refractive index of about 1.4 to 1.5, and that the encapsulation/stress relaxation layer 22 may be formed of SiON having a refractive index of about 1.6 to 1.9 ([0060]-[0061]).
Using the disclosed refractive index ranges, the difference between the refractive index of the planarization layer and the refractive index of the encapsulation layer is within ±20% of the refractive index of the planarization layer. For example, where the planarization layer has a refractive index of 1.5 and the encapsulation layer has a refractive index of 1.8, the difference is 0.3, which corresponds to 20% of 1.5.
Maeda further teaches that selecting refractive indices in this manner reduces interface reflection and improves focusing properties of the image sensor device [0061].
Regarding claim 7, Mouli in view of Maeda discloses the image sensor substantially as recited in claim 1. Maeda further discloses that planarization layer 21 is formed over the stepped topography of underlying color filter layer 20 in order to planarize and smooth the surface for subsequent optical layer formation. One of ordinary skill in the art would have understood that the planarization layer requires sufficient thickness to fill and smooth the stepped topography generated by the underlying color filter structures.
Maeda further discloses that overlying layer 22 functions primarily as a stress-relaxation and protective layer ([0060]-[0061]. One of ordinary skill in the art would have further understood that such protective/interface layers are conventionally formed as relatively thin films because they are not intended to substantially planarize underlying topography.
Accordingly, the combined teachings of Mouli and Maeda reasonably suggest a structure in which the thickness of the encapsulation layer is less than the thickness of the planarization layer.
Regarding claim 9, Mouli in view of Maeda discloses the image sensor substantially as recited in claim 1. Maeda further teaches that the planarization layer functions to planarize and smooth the uneven surface profile generated by the underlying color filter structures for subsequent formation of overlying optical layers.
Thus, one of ordinary skill in the art would have understood that the thickness of the planarization layer directly affects the ability of the layer to adequately cover, fill, and level the stepped topography of the underlying color filter layer and thereby affects optical uniformity and manufacturability of the image sensor structure.
Accordingly, the thickness of the planarization layer would have been recognized as a result-effective variable, and selecting an appropriate planarization layer thickness, including a thickness within the claimed range of about 300 nm to about 5 μm, would have constituted routine optimization achievable through ordinary experimentation to obtain suitable planarization performance and optical characteristics.
Applicant has not demonstrated that the claimed thickness range is critical or yields unexpected results relative to the prior art. See In re Woodruff, 919 F.2d 1575, 1578, 16 USPQ2d 1934, 1936 (Fed. Cir. 1990); In re Boesch, 617 F.2d 272, 276, 205 USPQ 215, 219 (CCPA 1980).
Regarding claim 11, Mouli in view of Maeda discloses the image sensor substantially as recited in claim 1, Mouli further discloses encapsulation layer thickness = about 50 Å to about 200 Å [0038]; and photonic crystal layer thickness = about 100 Å to about 5000 Å [0040].
Accordingly, one of ordinary skill in the art would have understood that incorporating Maeda’s planarization layer and encapsulation layer stack into Mouli’s structure would provide the claimed layered optical stack beneath the nano-photonic lens array.
Further, Mouli expressly discloses embodiments in which encapsulation layer 205 may have a thickness of approximately 200 Å while photonic crystal layer 261 may have a thickness of approximately 100 Å. In light of such teachings, one of ordinary skill in the art would have understood that incorporating Maeda’s planarization layer beneath Mouli’s encapsulation layer necessarily increases the cumulative thickness of the planarization layer and encapsulation layer stack relative to Mouli’s disclosed photonic crystal layer thickness, including embodiments in which the combined thickness of the planarization layer and encapsulation layer is equal to or greater than the thickness of the nano-photonic lens array.
Regarding claim 13, Mouli in view of Maeda discloses the image sensor substantially as recited in claim 1. Mouli further discloses an etch stop layer 265 arranged between encapsulation layer 205 and nano-photonic lens array 260′ (Fig. 7). Specifically, the layer 265 is disposed above encapsulation layer 205 and beneath nano-photonic lens array 260′.
Thus, one of ordinary skill in the art would have understood that layer 265 functions as an etch stop and protective layer during formation and etching of the overlying nano-photonic structures because layer 265 is positioned between the underlying optical layers and the patterned nano-photonic structures.
Maeda further confirms the conventional use of protective inorganic layers within layered optical stack structures during fabrication of overlying optical structures. See para. [0057].
Accordingly, the combined teachings of Mouli and Maeda disclose or at least reasonably suggest an etch stop layer arranged between the encapsulation layer and the nano-photonic lens array, as recited in claim 13.
Regarding claim 14, Mouli in view of Maeda discloses the image sensor substantially as recited in claim 1. Mouli further discloses wherein the nano-photonic lens array includes a first pattern of nano structures corresponding to a respective first pixel of the plurality of first pixels, and a second pattern of nano structures corresponding to a respective second pixel of the plurality of second pixels [0034]/[0035],
wherein the first pattern of nano structures and the second pattern of nano structures are disposed next to each other [0034]/[0035], and
wherein the first pattern of nano structures and the second pattern of nano structures condense the incident light onto the respective first pixel of the plurality of first pixels and the respective second pixel of the plurality of second pixels, respectively [0034]/[0059].
Regarding claim 15. Fig 4A (a detail portion view of Fig 7) and Fig 7 of Mouli disclose an image sensor comprising:
a sensor substrate 1 including a plurality of first pixels for sensing light of a first wavelength band ([0034]/[0035]/[0062]: Fig 7 shows only a portion of image sensor pixel array and includes pixel cells 10, the array is similar to array 100 in Fig 1A. And the pixel cells 10 receive different wavelengths of light, such as red, green, blue. Thus, the red pixels of the array is a plurality of first pixels) and a plurality of second pixels for sensing light of a second wavelength band that is different from the first wavelength band (the green pixels of the array is a plurality of second pixels);
a color filter layer 30 on the sensor substrate, the color filter layer including a plurality of color filters [0062];
a transparent encapsulation layer 205 arranged on the color filter layer (Mouli teaches that layer 205 may include SiO₂ [0038]. One of ordinary skill in the art would have understood that SiO₂ disposed within the optical path beneath nano-photonic structures is transparent to visible light. Further, claim 15 merely recites a “transparent encapsulation layer” without specifying any required structural or functional limitation beyond positional arrangement within the optical stack. Accordingly, layer 205 reasonably corresponds to the claimed transparent encapsulation layer under the broadest reasonable interpretation);
an etch stop layer 265 arranged on the transparent encapsulation layer (Fig. 7: layer 265 is disposed above layer 205 and beneath nano-photonic lens array 260′. One of ordinary skill in the art would have understood that layer 265 functions as an etch stop and protective layer during formation and etching of the overlying nano-photonic structures); and
a nano-photonic lens array 260′ [0050] arranged on the etch stop layer, the nano-photonic lens array including a plurality of nano-structures arranged to condense incident light onto the plurality of first pixels and the plurality of second pixels ([0059], claim 1).
Maeda further confirms the conventional use of protective inorganic layers within laminated optical stack structures during fabrication of overlying optical structures. Specifically, Maeda discloses a laminate structure including an organic material layer and an inorganic material layer [0057], which further supports the use of an etch stop/protective layer between underlying optical layers and overlying nano-photonic structures.
Thus, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to utilize the layered optical stack structure taught by Mouli, as further confirmed by Maeda, in order to improve manufacturability and protect underlying optical layers during nano-photonic patterning and etching processes.
Regarding claim 16, Mouli in view of Maeda discloses the image sensor substantially as recited in claim 15, Mouli discloses wherein the transparent encapsulation layer includes an inorganic material [0038].
Regarding claim 17, Mouli in view of Maeda discloses the image sensor substantially as recited in claim 16. Mouli discloses the transparent encapsulation layer only includes the inorganic material ([0038]: SiO2).
Regarding claim 18, Mouli in view of Maeda discloses the image sensor substantially as recited in claim 15. Mouli further discloses the encapsulation layer is in contact with the color filter layer (Fig 7).
Regarding claim 20. Fig 11 (a portion of an image sensor array) and Fig 14 (a block diagram of an image sensor including Fig 11) of Mouli disclose An electronic apparatus (Fig 14) comprising:
a lens assembly 20 for forming an optical image of a subject [0050];
an image sensor (the structure below 20) for converting the optical image formed by the lens assembly into an electrical signal ([0050]: via 12); and
a processor configured to process a signal generated by the image sensor (Fig 14),
wherein the image sensor comprises:
a sensor substrate 1 including a plurality of pixels sensing light ([0034]/[0035]/[0062]: Fig 11 shows only a portion of image sensor pixel array and includes pixel cells 10, the array is similar to array 100 in Fig 1A. And the pixel cells 10 receive different wavelengths of light, such as red, green, blue, which forms a plurality of pixels);
a color filter layer 30 on the sensor substrate, the color filter layer including a plurality of color filters [0062];
a transparent planarization layer 5 arranged on the color filter layer (the layer 5 is located in the incident light path between nano-photonic lens and the image sensor. Thus, one of ordinary skill in the art would have understood that 5 is essentially transparent);
a transparent encapsulation layer 176 (layer 176 is disposed between underlying optical structures and nano-photonic lens array 1101) arranged on the planarization layer (the 176 is located in the incident light path between nano-photonic lens and the image sensor. Thus, one of ordinary skill in the art would have understood that 176 is essentially transparent); and
a nano-photonic lens array 1101 [0061] arranged on the encapsulation layer and including a plurality of nano-structures arranged to condense incident light onto the plurality of pixels ([0059], claim 1).
But Mouli does not expressly disclose the transparent planarization layer is arranged between the color filter layer and the transparent encapsulation layer.
However, Fig 3 of Maeda discloses an image sensor structure including: a transparent planarization layer 21 disposed over the color filter layer 20, and an transparent encapsulation layer 22 disposed over the planarization layer [0051]. Maeda further teaches that these layers are optically transparent and suitable for use in image sensor optical structures. See paras. [0051] and [0061].
Thus, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to incorporate Maeda’s transparent planarization and encapsulation layer arrangement into Mouli’s electronic imaging apparatus for the purpose of improving surface planarization, optical transmission characteristics, stress relaxation, and manufacturability of the nano-photonic image sensor structure.
Claim 2 is rejected under 35 U.S.C. §103 as being unpatentable over Mouli (US 20060006485) in view of Maeda (US 20130134540) and further in view of (Suda US 20030063204).
Regarding claim 2, Mouli in view of Maeda discloses the image sensor substantially as recited in claim 1. But Mouli in view of Maeda does not explicitly disclose that the plurality of color filters include organic color filters including an organic dye or an organic pigment, as recited in claim 2.
However, Suda discloses a color filter layer 113 including organic color filters formed using organic dyes and/or organic pigments (Fig. 1, [0058]). Suda further teaches that such organic dye- and pigment-based color filters are suitable for wavelength-selective filtering and RGB color separation in image sensor devices.
Thus, it would have been obvious to one of ordinary skill in the art at the time the invention was made to modify the color filter layer of the image sensor of Mouli as modified by Maeda to employ the organic dye- or organic pigment-based color filters taught by Suda because organic pigment and dye color filters were well known and conventionally used in image sensors for wavelength-selective filtering and RGB color separation. One of ordinary skill in the art would have recognized that incorporating Suda’s known organic color filter materials into the Mouli/Maeda image sensor structure would have predictably provided suitable color filtering characteristics while remaining compatible with conventional image sensor fabrication techniques.
Further, the substitution of one known color filter material for another known color filter material constitutes the predictable use of prior art elements according to their established functions.
Claims 8 and 10 are rejected over Mouli (US 20060006485) in view of Maeda (US 20130134540) and further in view of Chen (US 20230012344).
Regarding claim 8, Mouli in view of Maeda discloses the image sensor substantially as recited in claim 1. But Mouli in view of Maeda does not expressly disclose that the encapsulation layer has a thickness of about 100 nm to about 500 nm.
Chen discloses an encapsulation layer 150 disposed over underlying planarization layer 140b and beneath overlying optical structures (Fig. 6F, [0028]) and [0030]. In particular, Fig. 6F illustrates the 150 covering and encapsulating the upper surface of layer 140b.
Applicant does not define the claimed encapsulation layer by any particular functional limitation or structural requirement other than being arranged on another layer. Accordingly, under the broadest reasonable interpretation, a layer disposed over and covering an underlying layer constitutes an encapsulation layer.
Chen further discloses that the encapsulation layer 150 has a thickness ranging from about 0.5 μm to about 1 μm. See para. [0030]. Because 0.5 μm corresponds to 500 nm, Chen teaches a thickness overlapping the claimed range of about 100 nm to about 500 nm.
Thus, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to utilize an encapsulation layer having a thickness within or near the claimed range because such layer thicknesses affect optical transmission, focal-point positioning, stress-relaxation properties, and manufacturability of image sensor optical stacks.
Applicant has not demonstrated that the claimed thickness range is critical or yields unexpected results relative to known optical stack configurations. See In re Woodruff, 919 F.2d 1575, 1578, 16 USPQ2d 1934, 1936 (Fed. Cir. 1990); In re Boesch, 617 F.2d 272, 276, 205 USPQ 215, 219 (CCPA 1980).
Regarding claim 10, Mouli in view of Maeda discloses the image sensor substantially as recited in claim 1, including: a color filter layer, a planarization layer, an encapsulation layer, and a nano-photonic lens array configured to condense incident light onto underlying pixel regions.
Mouli further teaches that the nano-photonic lens structures are configured to focus incident electromagnetic radiation onto underlying pixel cells [0059]. One of ordinary skill in the art would have understood that the relative positioning and cumulative thicknesses of optical stack layers disposed between the nano-photonic lens array and the underlying sensing regions directly affect focal-point positioning, optical focusing characteristics, and light-condensing efficiency of the image sensor structure.
Chen further discloses that the layer 150 is positioned between microlens 160 and photodiode 110 and that the 150 together with the microlens helps determine the focal point location within the photodiode [0028]. Chen additionally teaches that the 150 layer refracts incident light toward different focal point locations in response to applied electrical fields and thereby improves quantum efficiency and reduces crosstalk [0035].
Chen further teaches that different wavelengths of light exhibit different absorption depths and that optical structures may be tuned such that focal point locations correspond to different wavelength-dependent sensing regions [0018].
In particular, Chen teaches that microlenses ordinarily focus incident light at substantially equal focal point locations and that intervening optical structures permit tuning of focal point positioning for improved optical performance.
Accordingly, Chen confirms that focal-point positioning relative to intervening optical stack structures constitutes a known and routine optical design consideration in image sensor devices.
Furthermore, the claimed relationship of “within ±20%” encompasses a broad range of optical alignment relationships, including embodiments in which the difference is zero or near zero. Thus, the claim encompasses ordinary optical alignment configurations in which the cumulative optical stack thickness substantially corresponds to the focal length of the nano-photonic lens array.
Therefore, one of ordinary skill in the art before the effective filing date of the claimed invention would have found it obvious to select optical stack thicknesses and focal relationships such that the difference between:
• the sum of the thickness of the color filter layer,
• the thickness of the planarization layer,
• the thickness of the encapsulation layer,
and
• the focal length of the nano-photonic lens array
falls within the broadly recited ±20% range in order to obtain suitable focal alignment, wavelength-dependent optical focusing, improved light-condensing efficiency, and enhanced image sensor performance.
Applicant has not demonstrated that the claimed ±20% relationship is critical or yields unexpected results relative to known optical alignment and focal-position optimization techniques. Accordingly, claim 10 is unpatentable over Mouli in view of Maeda and further in view of Chen.
Claim 12 is rejected under 35 U.S.C. 103 as being unpatentable over Mouli (US 20060006485) in view of Maeda (US 20130134540), and further in view of Wang (US 20240021634).
Regarding claim 12. Mouli in view of Maeda discloses the image sensor substantially as recited in claim 1. But Mouli in view of Maeda does not expressly disclose each of the plurality of first pixels and second pixels comprises: a plurality of photosensitive cells that are two-dimensionally arranged and grouped in a first direction and a second direction and independently sense light, the second direction being perpendicular to the first direction; and an isolation electrically isolating the plurality of photosensitive cells.
However, Wang further discloses that groups of sensor units 100A, 100B, 100C, and 100D may constitute a pixel and are arranged in a 2×2 array structure (Figs. 1A and 1B, [0029]-[0030]). Wang further expressly teaches that each group of sensor units may include four sensor units arranged in a 2×2 array, such as a quad photodiode (QPD), or two sensor units arranged in a 1×2 array, such as a dual photodiode (DPD) [0030]. Wang additionally teaches that the sensor units are arranged in first and second directions within the image sensor array [0029]-[0030].
Wang further discloses deep trench isolation structures 106 electrically isolating adjacent sensing regions/sensor units (Fig. 1A; para. [0057]).
Accordingly, Wang discloses:
• a plurality of photosensitive cells that are two-dimensionally arranged and grouped in a first direction and a second direction and independently sense light, the second direction being perpendicular to the first direction; and
• an isolation electrically isolating the plurality of photosensitive cells.
Thus, it would have been obvious to one of ordinary skill in the art to incorporate Wang’s grouped and electrically isolated sensor-unit arrangement into the image sensor structure of Mouli in view of Maeda in order to improve optical sensing efficiency, pixel binning capability, and signal isolation between sensing regions.
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any extension fee pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to Changhyun Yi whose telephone number is (571)270-7799. The examiner can normally be reached Monday-Friday: 8A-4P.
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/Changhyun Yi/Primary Examiner, Art Unit 2812
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