Superconducting nanowire single photon detector （SNSPD）, as a new type of superconducting single photon detector （SPD）, has a broad application prospect in quantum communication and other fields. In order to prepa...Superconducting nanowire single photon detector （SNSPD）, as a new type of superconducting single photon detector （SPD）, has a broad application prospect in quantum communication and other fields. In order to prepare SNSPD with high performance, it is necessary to fabricate a large area of uniform meander nanowires, which is the core of the SNSPD. In this paper, we demonstrate a process of patterning ultra-thin NbN films into meander-type nanowires by using the nano- imprint technology. In this process, a combination of hot embossing nano-imprint lithography （HE-NIL） and ultraviolet nano-imprint lithography （UV-NIL） is used to transfer the meander nanowire structure from the NIL Si hard mold to the NbN film. We have successfully obtained a NbN nanowire device with uniform line width. The critical temperature （Tc） of the superconducting NbN meander nanowires is about 5 K and the critical current （lc） is about 3.5 μA at 2.5 K.展开更多
We report herein a rational approach for fabricating metal suspending nanostructures by nanoimprint lithography(NIL) and isotropic reactive ion etching(RIE).The approach comprises three principal steps:(1) mold fabric...We report herein a rational approach for fabricating metal suspending nanostructures by nanoimprint lithography(NIL) and isotropic reactive ion etching(RIE).The approach comprises three principal steps:(1) mold fabrication,(2) structure replication by NIL,and(3) suspending nanostructures creation by isotropic RIE.Using this approach,suspending nanostructures with Au,Au/Ti or Ti/Au bilayers,and Au/Ti/Au sandwiched structures are demonstrated.For Au nanostructures,straight suspending nanostructures can be obtained when the thickness of Au film is up to 50 nm for nano-bridge and 90 nm for nano-finger patterns.When the thickness of Au is below 50 nm for nano-bridge and 90 nm for nano-finger,the Au suspending nanostructures bend upward as a result of the mismatch of thermal expansion between the thin Au films and Si substrate.This leads to residual stresses in the thin Au films.For Au/Ti or Ti/Au bilayers nanostructures,the cantilevers bend toward Au film,since Au has a larger thermal expansion coefficient than that of Ti.While in the case of sandwich structures,straight suspending nanostructures are obtained,this may be due to the balance of residual stress between the thin films.展开更多
基金supported by the National Basic Research Program of China(Grant Nos.2011CBA00106 and 2009CB929102)the National Natural Science Foundation of China(Grant Nos.11104333 and 10974243)
文摘Superconducting nanowire single photon detector （SNSPD）, as a new type of superconducting single photon detector （SPD）, has a broad application prospect in quantum communication and other fields. In order to prepare SNSPD with high performance, it is necessary to fabricate a large area of uniform meander nanowires, which is the core of the SNSPD. In this paper, we demonstrate a process of patterning ultra-thin NbN films into meander-type nanowires by using the nano- imprint technology. In this process, a combination of hot embossing nano-imprint lithography （HE-NIL） and ultraviolet nano-imprint lithography （UV-NIL） is used to transfer the meander nanowire structure from the NIL Si hard mold to the NbN film. We have successfully obtained a NbN nanowire device with uniform line width. The critical temperature （Tc） of the superconducting NbN meander nanowires is about 5 K and the critical current （lc） is about 3.5 μA at 2.5 K.
基金Supported by the National Natural Science Foundation of China (Grant No. 20573002)the Major State Basic Research Development Program of China (973Pprogram) (Grant No. 2001CB6105)
文摘We report herein a rational approach for fabricating metal suspending nanostructures by nanoimprint lithography(NIL) and isotropic reactive ion etching(RIE).The approach comprises three principal steps:(1) mold fabrication,(2) structure replication by NIL,and(3) suspending nanostructures creation by isotropic RIE.Using this approach,suspending nanostructures with Au,Au/Ti or Ti/Au bilayers,and Au/Ti/Au sandwiched structures are demonstrated.For Au nanostructures,straight suspending nanostructures can be obtained when the thickness of Au film is up to 50 nm for nano-bridge and 90 nm for nano-finger patterns.When the thickness of Au is below 50 nm for nano-bridge and 90 nm for nano-finger,the Au suspending nanostructures bend upward as a result of the mismatch of thermal expansion between the thin Au films and Si substrate.This leads to residual stresses in the thin Au films.For Au/Ti or Ti/Au bilayers nanostructures,the cantilevers bend toward Au film,since Au has a larger thermal expansion coefficient than that of Ti.While in the case of sandwich structures,straight suspending nanostructures are obtained,this may be due to the balance of residual stress between the thin films.
