DETAILED ACTION
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on June 12, 2026, has been entered.
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Response to Amendment
Applicant’s amendments to the specification and drawings are acknowledged and do not add new matter.
Drawings
The prior drawing objection is withdrawn in view of the amended claims.
Claim Rejections - 35 USC § 112
The prior §112 rejections are withdrawn in view of the amended claims.
Claim Rejections - 35 USC § 103
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claims 1-3, 5-6, 8, and 9 are rejected under 35 U.S.C. 103 as being unpatentable over Sandoh et al. (US 2021/0104408) in view Bhardwaj et al. (US 6.051,503), Wu et al. (J. Appl. Phys. 108, 051101 (2010)), Laermer et al. (Plasma Process Polym. 2019;16c:1800207), Roxhed et al. (J. Micromech. Microeng. 17 (2007) 1087-1092), Craigie et al. (J. Vac. Sci. Technol. B 20(6), 2002), Mizuno et al. (US 2017/0263525), Puech et al. (US 2005/0103749), and Mori et al. (US 2014/0017902), all of record.
(Re Claims 1-3) Sandoh teaches a chip manufacturing method for dividing a wafer having a substrate with a plurality of devices along boundaries of the plurality of devices to manufacture individual chips, the chip manufacturing method comprising (see Figs. 1-8 and supporting text):
a first coating step of coating a front surface of the wafer with a water-soluble first protective film (water soluble resin 23/25, ¶¶34, 38, 39);
a groove forming step of applying a laser beam of such a wavelength as to be absorbed in the wafer through the first protective film such that regions of the first protective film overlapping with the boundaries and regions on the front surface side of the wafer are removed and grooves are formed in the wafer without dividing the wafer, wherein side surfaces and bottom surfaces of the grooves are damaged (Fig. 7A-7B, ¶¶49-53, the laser ablation used to form the groove causes damage to all exposed surfaces of the groove).
Sandoh then describes a conventional Bosch etch process to singulate the wafer (¶¶56-59) but does not provide a detailed discussion of exactly what happens during a conventional Bosch etching process or how known process variables influence the etched features. Sandoh is silent regarding a first plasma etching step, after the groove forming step, of subjecting the wafer to isotropic plasma etching from the front surface side of the wafer in a state in which the grooves are exposed to remove the damaged portions of the side surfaces and the bottom surfaces of the grooves, wherein undercuts are formed in the substrate on opposing sides of the grooves, the undercuts each extending at least partially under the first protective film; a second coating step, after the first plasma etching step, of coating side surfaces and bottom surfaces of the grooves with a second protective film, wherein a thickness of the second protective film is at least 20 nm; and a dividing step of sequentially repeating, after the second coating step, a second plasma etching step of subjecting the wafer to anisotropic plasma etching from the front surface side of the wafer so as to expose the bottom surfaces of the grooves, a third plasma etching step of subjecting the wafer to isotropic plasma etching from the front surface side of the wafer, and a third coating step of coating the side surfaces and the bottom surfaces of the grooves with a third protective film thinner than the second protective film, until the wafer is divided along the boundaries. Sandoh is also silent regarding (claim 3) further comprising: a second plasma etching step of subjecting the wafer to anisotropic plasma etching from the front surface side of the wafer so as to expose the bottom surfaces of the grooves, after the second coating step and before the dividing step, wherein conditions for the anisotropic plasma etching are different between the second plasma etching step and the dividing step.
A PHOSITA desiring to practice Sandoh’s Bosch etching would be motivated to look to related art to teach additional details of Bosch etching. Related art from Craigie et al. (see Fig. 1) and Laermer et al. (see Fig. 3) disclose the basic steps of a Bosch etch process. Craigie shows in Fig. 1, a first isotropic etch is performed through a mask using SF6, which makes a first scalloped feature, then the surfaces are passivated with a fluorocarbon polymer using C4F8, and then at the beginning of the next etch step “start of second etch”, a substrate bias is applied to anisotropically accelerate the ions to the bottom of the trench to break through the passivation layer while leaving the passivation on the sidewalls, once the passivation is removed from the bottom, the etching switches back to an isotropic etch using SF6 which forms an additional scalloped feature and the process is repeated. Laermer similarly shows this in Fig. 3 noting the anisotropic etching is used to remove the passivation from the bottom of the trench while it remains on the sidewalls, and then an isotropic etch using SF6 is performed and then the cycle repeats with another passivation step, another anisotropic etch and another isotropic etch, etc. From conventional Bosch etching, as shown by Laermer and Craigie, each of the plasma etching and deposition steps claimed flow naturally from performing the Bosch etch process. While much of the Bosch etching art considers the SF6 etching to be isotropic since the F etches the silicon in all directions leading to the scalloped sidewalls, even when a substrate bias is used, related art also teaches a more deliberately isotropic etch step wherein the substrate bias can be turned off for a more isotropic etch as disclosed by Roxhed et al. (see Section 2: Etch method and Table 1). Roxhed discloses one can simply decide what sidewall profile is desired and use the duration of the unbiased isotropic etch to advantageously control the profile. Craigie teaches the sidewall profile can also be controlled by the amount of the polymer layer formed by either depositing for longer durations or increasing the flow of the deposition gas (Fig. 2). Related art from Wu also recognizes the profile dependence on the duration of the individual etching and passivation steps (see pp. 7-8 Section D. Profile). Wu also recognizes the aspect ratio influences the etching and deposition (pp. 8-9 Section E. ARDE) and the higher aspect ratios (i.e. when etching a deeper feature), the etching at the bottom of the trench slows down as does the polymer deposition. This will naturally cause the polymer deposition step to form thinner and thinner layers the deeper the trench is etched. This is due to the reduced mass transport caused by the higher and higher aspect ratio features formed during the Bosch etching. Related art from Bhardwaj discloses a Bosch etch process wherein the deposition gas flow is reduced (and therefore the polymer thickness) for each cycle (see Fig. 20).
With respect to Sandoh’s groove forming step using laser ablation, this is well known to cause damage to the surfaces of the groove as evidenced by Mizuno (see Fig. 1B: DR). The first isotropic etching step of the Bosch etching will remove this damage and cause undercuts due to the isotropic etching, which is also similarly disclosed by Mizuno (¶29). Sandoh is silent regarding a thickness of the second protective film is at least 20 nm, although as discussed above, a PHOSITA can make the protective film any suitable thickness in order to control the etched sidewall profile. A PHOSITA may be motivated to look to related art to teach a suitable thickness and related art from Puech discloses a thickness of “a few tens of nm”, i.e. ~30 nm (¶53). Related art from Mori teaches the polymer may be 100 nm thick (¶175). In view of the prior art, choosing a thickness of 20 nm or more would be obvious and well within conventional thicknesses for the polymer.
In view of the prior art, a PHOSITA practicing Sandoh’s disclosed Bosch etching to singulate the wafer would naturally perform the claimed isotropic/anisotropic plasma etching and deposition steps as claimed. With respect to the third deposition being thinner than the second, this will flow naturally from simply running a constant Bosch process and will result from the increasing aspect ratios reducing the mass transport to the bottoms of the trenches along with some redeposition on the upper sidewalls. Additionally, one could deliberately change the deposition flow or duration to decrease the amount of deposition during the process to control the sidewall profile as desired according to Creigie and Bhardwaj. From this, a PHOSITA would recognize the passivation would naturally become thinner the deeper the trench is etched for a constant process, however one could also deliberately adjust the polymer thickness to control the sidewall profile. Regarding (claim 3), wherein conditions for the anisotropic plasma etching are different between the second plasma etching step and the dividing step, a PHOSITA would find this obvious in view of the teachings of Wu et al. and Bhardwaj. Wu recognizes (p. 8, col 1) that the profile changes with trench depth (aspect ratio) and to control for this, the bias voltage is increased the deeper the trench to achieve a vertical profile. In other related art, Bhardwaj teaches ramping the process parameters to achieve different sidewall angle and notching results, e.g. see Figs. 9 and 20. In view of Wu and Bhardwaj, a PHOSITA would find it obvious to make adjustments during the anisotropic etching steps to control the sidewall profile and prevent notching during the etching.
(Re Claims 5-6) wherein the second protective film has an insulating property; and wherein the second protective film contains carbon fluoride (the fluorocarbon polymer films CxFy are insulating films)
(Re Claims 8-9) wherein the water-soluble first protective film includes a liquid resin having a light absorbing agent (Sandoh: ¶34).
Claim 4 is rejected under 35 U.S.C. 103 as being unpatentable over Sandoh et al., Bhardwaj et al., Wu et al., Laermer et al., Roxhed et al., Craigie et al., Mizuno et al., Puech et al., and Mori et al., as applied above, and further in view of Kim et al. (US 2015/0262839), all of record.
(Re Claim 4) wherein an insulating layer is provided between the substrate and the plurality of devices.
Sandoh is silent regarding an insulating layer between the substrate and devices although Sandoh does disclose the device layer 15 includes dielectrics and interconnects (¶27) and that there is no limit on the material, shape, structure, size, and so forth of the substrate or the kind, quantity, shape, structure, size, arrangement, and so forth of the devices (¶28), thus there obviously may be a dielectric layer between the substrate and devices since the options are explicitly unlimited. A PHOSITA would recognize a SOI substrate is conventionally use for device isolation and may be used since the substrate and devices are essentially unlimited. Related art from Kim discloses an SOI wafer (¶¶27, 61) may be used as a device wafer when performing Bosch etching. When using an SOI wafer the insulating layer is between the device layer and the bulk substrate. A PHOSITA would find an SOI wafer obvious it use for it’s improved device isolation properties.
Response to Arguments
Applicant's arguments filed 6/12/2026 have been fully considered but they are not persuasive. Applicant argues the Sandoh does not teach the claimed invention, in particular because Sandoh does not provide an accurate depiction or discussion of the well-known damage occurring from the laser ablation, and lacks details which flow naturally from performing a conventional Bosch etch process. Applicant also argues Sandoh does not teach the protective layer thickness of at least 20 nm. With respect to the thickness, this limitation was previously in claim 7 and Puech and Mori were applied to teach the thickness, not Sandoh, now incorporated into the rejections of claims 1 and 2. Applicant further argues the additional references used in the rejection (Bhardwaj et al., Wu et al., Laermer et al., Roxhed et al., Craigie et al., Mizuno et al., and Mori et al.) do not teach features these references are not relied upon to teach. Applicant’s arguments are not persuasive. Sandoh’s laser ablation will cause the claimed damage in the groove and the first isotropic etching step of the subsequent Bosch etch will remove the damage and cause the undercuts as claimed, also see Mizuno et al. Mizuno et al. was not relied upon to teach applying a protective film to the undercuts or the first plasma step in conjunction with the second coating step. These next steps flow naturally from performing a Bosch etch process as disclosed by Bhardwaj et al., Wu et al., Laermer et al., Roxhed et al., and Craigie et al. In response to applicant's arguments against the references individually, one cannot show nonobviousness by attacking references individually where the rejections are based on combinations of references. See In re Keller, 642 F.2d 413, 208 USPQ 871 (CCPA 1981); In re Merck & Co., 800 F.2d 1091, 231 USPQ 375 (Fed. Cir. 1986). The test for obviousness is not whether the features of a secondary reference may be bodily incorporated into the structure of the primary reference; nor is it that the claimed invention must be expressly suggested in any one or all of the references. Rather, the test is what the combined teachings of the references would have suggested to those of ordinary skill in the art. See In re Keller, 642 F.2d 413, 208 USPQ 871 (CCPA 1981).
Conclusion
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/ERIK T. K. PETERSON/Primary Examiner, Art Unit 2898
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