CMOS Dual-Work-Function Engineering by Using Implanted Ni-FUSI
For the first time, a simple CMOS fully silicided (FUSI) process achieving n/pMOS band-edge work function was demonstrated, which is fully compatible with conventional CMOS process. Dual-work-function CMOS FUSI, with a wide range of 800 mV, was achieved by implantation of Yb into the poly of the nMOS gate (4.1-eV work function) and Ga into the poly of the pMOS gate (4.9-eV work function), respectively. The placement of the tuning elements at the metal/dielectric interface was engineered with the thermal budget, as well as the implant dose and species.
Demonstration of a New Approach Towards 0.25V Low-Vt CMOS Using Ni-Based FUSI
This report discusses a new and practical approach to implement low Vt bulk CMOS using Ni-based FUSI MOSFETs. On the nFET, we demonstrate for the first time that incorporating Yb by ion implantation can achieve similar reduction of effective work function (WF) compared to alloying making it a candidate for CMOS integration. We complement our previous work on WF modulation by Yb on NiSi/SiON with new data on NiSi/HfSiON and NiGeSi/HfSiON. On the pFET, we study the effect of Al and Pt on Ni-rich FUSI and integrate it with a SiGe-channel. Integration into our reference devices resulted in a Vt reduction from 0.55/0.61V down to 0.30/0.25V for nFET (NiSi:Yb gate) and pFET (Ni2 Si:Pt gate + SiGe channel) respectively on SiON without degradation of the dielectric integrity and long channel mobility, and without an increase in gate leakage and Dit
Experimental study on bond behavior between high-strength grout and deformed steel bars
Abstract Engineers use high-strength grout to connect precast concrete members for its low shrinkage and good fluidity. This paper designed 87 central pull-out specimens using the control variable method to investigate the influence of factors on the rebar-grout bond property such as compressive strength, steel grade, bar diameter, transverse stirrups, and bond length. The test result showed that improving grout compressive strength (85.8 MPa–122.7 MPa) cannot improve the bond strength, which was different from the previous conclusions of concrete pull-out tests. Simplified formulas were presented for calculating the characteristic values of bond strength, residual strength, peak slip, and relative slip of load-holding platform based on parameter analysis. Then, a constitutive model was proposed to predict the full-range bond stress-slip curve of high-strength grout and steel bar specimens from bearing to failure. Finally, FEA models were established to evaluate the applicability and accuracy of the constitutive model.