： We introduced a TaN/TiAl/top-TiN triple-layer to modulate the effective work function of a TiN-based metal gate stack by varying the TaN thickness and top-TiN technology process. The results show that a thinner TaN...： We introduced a TaN/TiAl/top-TiN triple-layer to modulate the effective work function of a TiN-based metal gate stack by varying the TaN thickness and top-TiN technology process. The results show that a thinner TaN and PVD-process top-TiN capping provide smaller effective work function （EWF）, and a thicker TaN and ALD-process top-TiN capping provides a larger EWF; here, the EWF shifts are from 4.25 to 4.56 eV. A physical understanding of the dependence of the EWF on the top-TiN technology process and TaN thickness is proposed. Compared with PVD-TiN room temperature process, the ALD-TiN 400 ℃ process provides more thermal budget. It would also promote more Al atoms to diffuse into the top-TiN rather than the bottom-TiN. Meanwhile, the thicker TaN prevents the Al atoms diffusing into the bottom-TiN. These facts induce the EWF to increase.展开更多
Ti ion implantation was implanted into PVD-TiN films using a metal vapor vacuum arc (MEVVA) ion source with a low implantation dose and at a time-averaged ion beam current density of 25|O.A-cm’2. The wear characteris...Ti ion implantation was implanted into PVD-TiN films using a metal vapor vacuum arc (MEVVA) ion source with a low implantation dose and at a time-averaged ion beam current density of 25|O.A-cm’2. The wear characteristics of the implanted zone was measured and compared to the performance of unimplanted zone by a pin-on-disc apparatus and an optical interference microscope. The structure of the implanted zone and unimplanted zone was observed by X-ray photoelectron spectroscopy (XPS) and high voltage electron microscopy (HVEM). The wear mechanisms of the TiN film after ion implantation were discussed according to the results of XPS and HVEM.展开更多
With the rapid development of the automobile industry in China, there is an ever-increasing demand for long-life cold working dies used for punching automobile components. However, the full potential of such advanced ...With the rapid development of the automobile industry in China, there is an ever-increasing demand for long-life cold working dies used for punching automobile components. However, the full potential of such advanced surface engineering technologies as PVD coatings and duplex surface treatments in cold work dies has not been realized. In the present study, Crl2MoV steel has been surface engineered by single PVD Ti/TiN coating and duplex treatment combining low temperature plasma nitriding (LTPN) with PVD Ti/TiN coatings. The properties of Ti/TiN coatings in terms of surface morphology, microhardness, load bearing capacity, bonding strength and wear resistance were evaluated by microhardness, scratch and wear tests. The experimental results show that PVD Ti/TiN coatings can significantly enhance the surface load bearing capacity (especially for duplex treatments) and wear resistance of Crl2MoV steel by more than one order of magnitude. This can be mainly attributed to the hard and well-adherent PVD Ti/TiN surface coatings and strong mechanical support of the LTPN sublayer. While two-body abrasive wear prevails for uncoated Crl2MoV, the micropolishing action of the counterface dominates in surface engineered material.展开更多
基金Project supported by the Important National Science&Technology Specific Projects(No.2009ZX02035)the National Natural Science Foundation of China(Nos.61176091,61306129)
文摘： We introduced a TaN/TiAl/top-TiN triple-layer to modulate the effective work function of a TiN-based metal gate stack by varying the TaN thickness and top-TiN technology process. The results show that a thinner TaN and PVD-process top-TiN capping provide smaller effective work function （EWF）, and a thicker TaN and ALD-process top-TiN capping provides a larger EWF; here, the EWF shifts are from 4.25 to 4.56 eV. A physical understanding of the dependence of the EWF on the top-TiN technology process and TaN thickness is proposed. Compared with PVD-TiN room temperature process, the ALD-TiN 400 ℃ process provides more thermal budget. It would also promote more Al atoms to diffuse into the top-TiN rather than the bottom-TiN. Meanwhile, the thicker TaN prevents the Al atoms diffusing into the bottom-TiN. These facts induce the EWF to increase.
基金supported partly by Science and Technology Engineering of Nantong(2004032)Nantong Institute of Technology(200347)
文摘Ti ion implantation was implanted into PVD-TiN films using a metal vapor vacuum arc (MEVVA) ion source with a low implantation dose and at a time-averaged ion beam current density of 25|O.A-cm’2. The wear characteristics of the implanted zone was measured and compared to the performance of unimplanted zone by a pin-on-disc apparatus and an optical interference microscope. The structure of the implanted zone and unimplanted zone was observed by X-ray photoelectron spectroscopy (XPS) and high voltage electron microscopy (HVEM). The wear mechanisms of the TiN film after ion implantation were discussed according to the results of XPS and HVEM.
文摘With the rapid development of the automobile industry in China, there is an ever-increasing demand for long-life cold working dies used for punching automobile components. However, the full potential of such advanced surface engineering technologies as PVD coatings and duplex surface treatments in cold work dies has not been realized. In the present study, Crl2MoV steel has been surface engineered by single PVD Ti/TiN coating and duplex treatment combining low temperature plasma nitriding (LTPN) with PVD Ti/TiN coatings. The properties of Ti/TiN coatings in terms of surface morphology, microhardness, load bearing capacity, bonding strength and wear resistance were evaluated by microhardness, scratch and wear tests. The experimental results show that PVD Ti/TiN coatings can significantly enhance the surface load bearing capacity (especially for duplex treatments) and wear resistance of Crl2MoV steel by more than one order of magnitude. This can be mainly attributed to the hard and well-adherent PVD Ti/TiN surface coatings and strong mechanical support of the LTPN sublayer. While two-body abrasive wear prevails for uncoated Crl2MoV, the micropolishing action of the counterface dominates in surface engineered material.
