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We present the FinFET process integration technology including improved sidewall transfer (SWT) process applicable to both fins and gates. Using this process, the uniform electrical characteristics of the ultra-small FinFETs of 15nm gate length and 10nm fin width have been demonstrated.A new process technique for the selective gate sidewall spacer formation (spacer formation only on the gate sidewall, no spacer on the fin sidewall) is also demonstrated for realizing low-resistance elevated source/drain (S/D) extension. IntroductionFinFETs are promising candidates for sub-20nm scale CMOS devices because of their excellent scalability [1-8]. Primary challenges for FinFETs are the formation of uniform and narrow fins and the reduction of S/D series resistance. The sidewall transfer (SWT) process was proposed to form sub-lithographic fins and reduce the line edge roughness of the fins (Fig.1) [1]. However, the integration technology for the application of SWT process to both fin and gate formation has not been reported yet. On the other hand, it is necessary to deposit silicon selectively on the narrow fins for the reduction of the series resistance by increasing the fin width in S/D regions. However, this process has been very difficult because of the residue of gate sidewall spacer material left on the fin sidewall and the agglomeration of narrow fins.In this paper, we report the FinFET process integration technology including improved SWT process applied to both fins and gates. We also present the device characteristics of the ultra-small FinFET with 15nm gate length and 10nm fin width. A new process technique for the selective gate sidewall spacer formation is also proposed and the advantages of this new approach are experimentally demonstrated.

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The present paper describes a method for determining geometries of gear-honing wheels used in the final process for manufacturing automotive transmission gears. Inappropriate geometries of gear-honing wheels could cause large undulations on finished gear-tooth flanks, and the finished gear would be out of the required accuracy. In such cases, the geometries of gear-honing wheels are required to be modified iteratively until the finished gears have sufficient accuracy. The change in meshing stiffness of a gear-honing wheel and a finished gear significantly affects the rotational synchronization. The poor rotation synchronization could cause the large undulation on a finished gear-tooth flank, to be different from the target micro geometries. This paper presented a geometrical approach that was proposed for a determination method of gear-honing-wheel geometries. The method allows the meshing stiffness to be balanced. Gear-honing wheels designed with the proposed method induced the desired micro geometries of finished gear-tooth flanks in gear-honing experiments. Therefore, the proposed method with the geometrical approach could be useful for the determination of gear-honing-wheel geometries.