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 .
Election/Restrictions
Applicant’s election without traverse of Group I, claims 1-10 in the reply filed on March 21, 2026 is acknowledged. Accordingly, claims 11-20 have been withdrawn from consideration.
Priority
Receipt is acknowledged of certified copies of papers required by 37 CFR 1.55.
Information Disclosure Statement
As of March 31, 2026, no information disclosure statement has been made of record.
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.
Claim(s) 1-4, 7, and 10 are is/are rejected under 35 U.S.C. 103 as being unpatentable over Sung et al. (US 2015/0179796 A1) (“Sung”), in view of Lu et al. (US 2012/0309171 A1) (“Lu”).
Regarding claim 1, Sung teaches at least in figure 1:
a gate structure disposed on a substrate (108);
a first epitaxial layer (106a; ¶ 0018) disposed in the substrate (102) and at two sides of the gate structure (108);
a second epitaxial layer (106b) disposed on the first epitaxial layer (106a); and
a cap layer (106c) disposed on the second epitaxial layer (106b).
Sung does not teach:
wherein an included angle between a surface of the second epitaxial layer and a horizontal direction is 15 degrees to 35 degrees.
This is because Sung teaches:
The angle can be 90-45 degrees.
Lu teaches at least in figure 5:
wherein an included angle between a surface of the epitaxial layer (36) and a horizontal direction is 15 degrees to 35 degrees (¶ 0018, where the angle can range from 15-60 degrees).
It would have been obvious to one of ordinary skill in the art to combine Lu with Sung as Lu teaches the angle of the epitaxial layer and the horizontal direction results in different faces of the epitaxial layer being exposed. ¶ 0018. Therefore, it would have been obvious to one of ordinary skill in the art to choose the angle of the epitaxial layer to coincide with their choice of which face they want to use on the epitaxial layer.
The combination of Lu and Sung would result in:
the second epitaxial layer (Sung 106b) having the claimed angle (Lu ¶ 0018).
Regarding claim 2, Sung teaches at least in figure 1:
wherein an included angle between a surface of the cap layer (106c) and the horizontal direction is 0 degrees to 5 degrees (figure 1 shows the cap layer as flat or 0 degrees).
Regarding claim 3, Sung teaches at least in figure 1:
wherein a material of the cap layer comprises silicon (¶ 0038 where 106c can be pure silicon epitaxial layer), and
a crystal orientation of the surface of the cap layer is (100) (it would have been obvious to one of ordinary skill in the art that 106c could have a crystal orientation of (100). This is because as stated in claim 1 Sung teaches the angle determines which face is presented on top. In addition, (100) single crystal silicon is one of the most commonly used silicon crystal faces. See Sung ¶ 0018, where (100) silicon is used as the substrate. Therefore, it would have been obvious for one of ordinary skill in the art to try and use (100) silicon as this is a well-known face of silicon, and is routinely used.).
Regarding claim 4, Sung does not expressly teach:
wherein a thickness of the second epitaxial layer (106b) in a direction perpendicular to the horizontal direction is 30 angstroms to 150 angstroms.
However, Sung teaches that the total depth of the source/drain region is approximately 300-1000Å. ¶ 0063. Further, Sung teaches the germanium concentration in each layer of the source/drain region is a dependent upon the depth of each source/drain region. Figure 2, and ¶¶ 0023-25. Therefore, it would have been obvious for one of ordinary skill in the art to use routine skill in the art and optimize the depth of the second epitaxial layer and its corresponding Ge concentration based upon the required strain they want each region/layer of the source drain region to have in regards to the channel. ¶¶ 0020-22. Therefore, claim 4 would have been a matter of optimization to one of ordinary skill in the art based upon their requirements for the device of Sung.).
Regarding claim 7, Sung teaches at least in figure 1:
further comprising (detailed below):
a spacer (116) surrounding the gate structure (108).
Regarding claim 10, Sung does not teach:
wherein a material of the second epitaxial layer comprises silicon germanium, and a crystal orientation of the surface of the second epitaxial layer is (311).
However, based upon the analysis of claim 1, it would have been obvious to one of ordinary skill int eh art using Lu that they could have made the second epitaxial layer have the claimed surface plane based upon the angle the top portion of the second epitaxial layer is made to.
Claim(s) 5-6, 8-9 are is/are rejected under 35 U.S.C. 103 as being unpatentable over Sung, in view of Lu, in view of Kwok et al. (US 2012/0205715 A1) (“Kwok”).
Regarding claim 5, Sung is silent with respect to the limitation:
wherein a thickness of the cap layer in a direction perpendicular to the horizontal direction is 100 angstroms to 200 angstroms.
Therefore, one of ordinary skill in the art would be motivated to find another reference to teach this thickness. This search would lead them to find Kwok. Kwok is directed to similar technology as Sung, epitaxially grown source/drain regions.
Kwok teaches at least in figure 8:
wherein a thickness of the cap layer (238) in a direction perpendicular to the horizontal direction is 100 angstroms to 200 angstrom (¶ 0029).
It would have been obvious to one of ordinary skill in the art to combine Kwok with Sung for the aforementioned reasons.
Regarding claim 6, the combination of references teaches:
wherein a total thickness of the second epitaxial layer (Sung 106b) and the cap layer (106c) in a direction perpendicular to the horizontal direction is 130 angstroms to 350 angstroms (This would have been obvious for the reasons stated in claim 4. In addition it would have been obvious based upon the thicknesses given in Kwok, where V3 can be 250-550 angstroms and the thickness of 238 can be 80-200 angstroms. Therefore, Kwok also teaches this limitation).
Regarding claim 8, the combination of references teaches:
wherein a ratio of a total thickness of the second epitaxial layer and the cap layer in a direction perpendicular to the horizontal direction to a thickness of a sidewall of the spacer in the horizontal direction is 1 to 2 (this limitation is obvious as it is considered an optimization and/or a change in size and proportion of the spacer to the width of the epitaxial layers. This optimization is based upon the distance between the gates. This distance is a standard process variable used in fabricating semiconductors. This standard process variable is based upon the process node used to construct the device of the prior art. See MPEP 2144.04(IV)(A), where the only difference between the prior art and the claims was a recitation of relative dimensions of the claimed device and a device having the claimed relative dimensions would not perform differently than the prior art device, the claimed device was not patentably distinct from the prior art device. Citing Gardner v.TEC Syst., Inc., 725 F.2d 1338 (Fed. Cir. 1984)).
Regarding claim 9, Kwok teaches at least in figure 8:
wherein a thickness of a sidewall of the spacer (230) in the horizontal direction is 150 angstroms to 200 angstroms (¶ 0013).
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to VINCENT WALL whose telephone number is (571)272-9567. The examiner can normally be reached Monday to Thursday at 7:30am to 2:30pm PST. Interviews can be scheduled on Tuesday thru Thursday at 10am PST or 2pm PST.
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/VINCENT WALL/Primary Examiner, Art Unit 2898
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