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.
Claim(s) 1, 3-6 and 14-17 is/are rejected under 35 U.S.C. 103 as being unpatentable over Wu et al. (CN-109786318-A) in view of Noguchi et al. (US 2004/0152256).
Regarding claim 1, Wu et al. discloses, as shown in Figures 2A-4B, a method comprising:
depositing a dielectric (190) on gate structures (G) and source/drain (S/D) structures (170,170) (Fig. 2B);
forming an opening (192) in the dielectric to expose the S/D structures (Fig. 2L);
forming a silicide (C) on the S/D structures (Fig. 2M);
depositing ruthenium (420, page 20) on a bottom surface and sidewall surfaces of the opening (Fig. 4A);
depositing cobalt (290, page 20) on the ruthenium to fill the opening (Fig. 4A);
planarizing the cobalt and the ruthenium to form S/D conductive structures so that a top surface of the S/D conductive structures are coplanar with a top surface of the dielectric (Fig. 4B).
Wu et al. does not disclose reflowing the cobalt. However, Noguchi et al. discloses a method of filling an opening (17) with a filling conductive material (19) and then reflow the filling conductive material (19). Note Figures 3-4 and [0073] of Noguchi et al. Therefore, it would have been obvious to one of ordinary skill in the art at the time the invention was made to reflow the filling conductive material of Wu et al., such as taught by Noguchi et al. in order improve the wettability and eliminate voids in the filling conductive material.
Regarding claim 3, Wu et al. and Noguchi et al. disclose reflowing the cobalt comprises annealing the ruthenium and the cobalt at a temperature between about 250° C. and about 500° C [0073].
Regarding claim 4, since Wu et al. and Noguchi et al. disclose the same structure as the claimed invention, it is inherent that reflowing the cobalt comprises reducing a resistivity of the ruthenium (wettability and voids-free).
Regarding claim 5, since Wu et al. and Noguchi et al. disclose the same structure as the claimed invention, it is inherent that reflowing the cobalt comprises diffusing cobalt atoms from the cobalt in the ruthenium.
Regarding claim 6, Wu et al. and Noguchi et al. disclose the method further comprising:
depositing another dielectric (250) on the dielectric (Fig. 6);
forming another opening in the dielectric and the other dielectric to expose the gate structures (Fig. 6);
depositing ruthenium (420, same Figures 4A-4B) on a bottom surface and sidewall surfaces of the other opening;
depositing cobalt (270, same Figures 4A-4B) on the ruthenium to fill the other opening;
reflowing the cobalt in the other opening (reflowing per Noguchi et al.); and
planarizing the cobalt and ruthenium to form a gate conductive structure (S) with a top surface coplanar with a top surface of the other dielectric (Figures 4A-4B, 6).
Regarding claim 14, Wu et al. discloses a method comprising:
forming a gate structure (G1) and a source/drain (S/D) structure (170) on a substrate (110);
forming a first conductive structure (S) on the S/D structure and extending through a first dielectric layer (190,250 (Figures 4A-5);
forming a second conductive structure (S) on the gate structure (G1) and extending through the first dielectric layer and a second dielectric layer (240) (Figure 6);
wherein each of the first conductive structure and the second conductive structure, and comprises: a ruthenium liner (420, page 20) in contact with one or more of the first dielectric layer and the second dielectric layer; and a cobalt metal (290, page 20) in contact with the ruthenium liner.
Wu et al. does not disclose forming a third conductive structure on the first conductive structure and the third conductive structure comprises: a ruthenium liner in contact with one or more of the first dielectric layer and the second dielectric layer, and a cobalt metal in contact with the ruthenium liner. However, Noguchi et al. discloses a method comprising a third conductive structure (20) on a first conductive structure (13,13a). Note Figures 4-5 of Noguchi et al. Therefore, it would have been obvious to one of ordinary skill in the art at the time the invention was made to a third conductive structure on the first conductive structure, such as taught by Noguchi et al. in order to provide the desired circuit connection. Also, it would haven obvious to form the third conductive structure comprises: a ruthenium liner in contact with one or more of the first dielectric layer and the second dielectric layer, and a cobalt metal in contact with the ruthenium liner by repeating the process of forming the first and second conductive structure in order to save the process steps.
Regarding claim 15, Wu et al. and Noguchi et al. disclose further comprising forming a ruthenium liner on a bottom surface and sidewall surfaces of each of the first conductive structure, the second conductive structure, and the third conductive structure (Figures 4A-6).
Regarding claim 16, Wu et al. and Noguchi et al. do not disclose forming the ruthenium liner comprises forming a ruthenium liner with a cobalt concentration. However, However, Noguchi et al. discloses a method of filling an opening (17) with a filling conductive material (19) and then reflow the filling conductive material (19). Note Figures 3-4 and [0073] of Noguchi et al. Therefore, it would have been obvious to one of ordinary skill in the art at the time the invention was made to reflow the filling conductive material of Wu et al., such as taught by Noguchi et al. in order improve the wettability and eliminate voids in the filling conductive material so that the cobalt would diffuse into the ruthenium liner.
Regarding claim 17, Wu et al. and Noguchi et al. further comprising forming a width of a top surface of the first conductive structure greater than a width of a bottom surface of the first conductive structure (Figures 4A-6).
Claim(s) 2 and 20 is/are rejected under 35 U.S.C. 103 as being unpatentable over Wu et al. (CN-109786318-A) in view of Noguchi et al. (US 2004/0152256) and further in view of You et al. (PN 6,756,672).
Regarding claim 2, Wu et al. and Noguchi et al. disclose the claimed invention including the method as explained in the above rejection. Wu et al. and Noguchi et al. do not disclose depositing the ruthenium comprises depositing the ruthenium so that a first thickness of the ruthenium on the bottom surface of the opening is different from a second thickness of the ruthenium on the sidewall surfaces. However, You et al. discloses a method comprising depositing the barrier layer (120) so that a first thickness of the barrier layer on the bottom surface of the opening (116,146) is different from a second thickness of the barrier on the sidewall surfaces. Note Figures 4H and 5L. Therefore, it would have been obvious to one of ordinary skill in the art at the time the invention was made to depositing the barrier layer of Wu et al. and Noguchi et al. having a first thickness of the barrier layer on the bottom surface of the opening is different from a second thickness of the barrier on the sidewall surfaces, such as taught by You et al. in order to further improve the wettability of the barrier layer.
Regarding claim 20, Wu et al. and Noguchi et al. disclose the claimed invention including the method as explained in the above rejection. Wu et al. and Noguchi et al. do not disclose forming a first thickness of the ruthenium liner on a bottom surface contacting the gate structure greater than a second thickness of the ruthenium liner on the bottom surface contacting the first dielectric between the S/D structure and the gate structure. However, You et al. discloses a method comprising depositing the barrier layer (120) so that a first thickness of the barrier layer on the bottom surface of the opening (116,146) is greater than a second thickness of the barrier on the sidewall surfaces. Note Figures 4H and 5L. Therefore, it would have been obvious to one of ordinary skill in the art at the time the invention was made to form the barrier layer of Wu et al. and Noguchi et al. having a first thickness of the barrier layer on the bottom surface of the opening is greater than a second thickness of the barrier on the sidewall surfaces, such as taught by You et al. in order to further improve the wettability of the barrier layer.
Claim(s) 18-19 is/are rejected under 35 U.S.C. 103 as being unpatentable over Wu et al. (CN-109786318-A) in view of Noguchi et al. (US 2004/0152256) and further in view of Son et al. (US 2013/0161722).
Regarding claim 18, Wu et al. and Noguchi et al. disclose the claimed invention including the method as explained in the above rejection. Wu et al. and Noguchi et al. do not disclose forming the second conductive structure taller than the first conductive structure and the third conductive structure. However, Son et al. discloses a method of forming the second conductive structure (454,456) taller than the first conductive structure (280) and the third conductive structure (280). Note Figures 1-2 of Son et al. Therefore, it would have been obvious to one of ordinary skill in the art at the time the invention was made to form the second conductive structure of Wu et al. and Noguchi et al. taller than the first conductive structure and the third conductive structure, such as taught by Son et al. in order to have the desired structure.
Regarding claim 19, Wu et al. and Noguchi et al. disclose the claimed invention including the method as explained in the above rejection. Wu et al. and Noguchi et al. do not disclose forming the second conductive structure in contact with the first conductive structure. However, Son et al. discloses a method comprising forming the second conductive structure (454, 456) in contact with the first conductive structure (280). Note Figures 1-2 of Son et al. Therefore, it would have been obvious to one of ordinary skill in the art at the time the invention was made to form the device of Wu et al. and Noguchi et al. comprising forming the second conductive structure in contact with the first conductive structure, such as taught by Son et al. in order to have the desired connection.
Allowable Subject Matter
Claims 7-13 are allowed.
The following is a statement of reasons for the indication of allowable subject matter:
Applicant' s claims 7-13 are allowable over the references of record because none of these references disclose or can be combined to yield the claimed method comprising forming a shared conductive structure in the first dielectric contacting the gate structure and the source/drain (S/D) structure, the shared conductive structure comprises a ruthenium liner on a bottom surface and sidewall surfaces of the shared conductive structure and contacting the first dielectric and the etch stop layer, a first thickness of the ruthenium liner on the bottom surface contacting the S/D structure is greater than a second thickness of the ruthenium liner on the bottom surface contacting the first dielectric between the S/D structure and the gate structure, and a cobalt metal layer in contact with the ruthenium liner, in combination with the remaining claimed limitations of claim 7.
Conclusion
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/HUNG K VU/ Primary Examiner, Art Unit 2897