Current-voltage electrical characteristics of Er silicide/Si（001） nanocontacts are measured in situ in a scanning tunneling microscopy system. Introduced as a new technique to suppress surface leakage conduction on...Current-voltage electrical characteristics of Er silicide/Si（001） nanocontacts are measured in situ in a scanning tunneling microscopy system. Introduced as a new technique to suppress surface leakage conduction on Si（001）,a silver wetting layer is evaporated onto the substrate surface kept at room temperature with Er Si2 nanoislands already existing. The effects of the silver layer on the current-voltage characteristics of nanocontacts are discussed.Our experimental results reveal that the silver layer at coverage of 0.4–0.7 monolayer can suppress effectively the current contribution from the surface conduction path. After the surface leakage path of nanocontacts is obstructed, the ideality factor and the Schottky barrier height are determined using the thermionic emission theory, about 2 and 0.5 eV, respectively. The approach adopted here could shed light on the intrinsic transport properties of metal-semiconductor nanocontacts.展开更多
A "T" shaped micro-gap was fabricated by mechanical polishing between two Cu film electrodes on the surface of single-sided bonded copper.A nano-gap was then fabricated in the prepared micro-gap by resistanc...A "T" shaped micro-gap was fabricated by mechanical polishing between two Cu film electrodes on the surface of single-sided bonded copper.A nano-gap was then fabricated in the prepared micro-gap by resistance feedback controlled electroplating.Finally Ni 80 Fe 20 ferromagnetic nanocontacts of several sizes were fabricated in the prepared nano-gap by resistance feedback controlled electroplating.The magnetoresistance of each Ni 80 Fe 20 ferromagnetic nanocontact was not related to its size.Fabrication of the Ni 80 Fe 20 ferromagnetic nanocontacts in the nano-gap can reduce the contribution of magnetostriction to the magnetoresistance.The magnetoresistance values of the Ni 80 Fe 20 ferromagnetic nanocontacts were as high as those of the Ni ferromagnetic nanocontacts.This implies that the contribution of magnetostriction to the ballistic magnetoresistance of the ferromagnetic nanocontacts can be neglected.The ferromagnetic nanocontacts fabricated in this study,and in other cases,have two anisotropic interfaces on the sides of the nanocontacts.However,the magnetic field can alter the contribution of the interaction between the two anisotropic interfaces to the ballistic magnetoresistance of the ferromagnetic nanocontacts,and this effect can not be ruled out yet.展开更多
Ag nanowires(AgNWs)have shown great application value in the field of flexible electronics due to their excellent optical and electrical properties,and the quality of its joints of AgNWs in the thin film network direc...Ag nanowires(AgNWs)have shown great application value in the field of flexible electronics due to their excellent optical and electrical properties,and the quality of its joints of AgNWs in the thin film network directly plays a key role in its performance.In order to further improve the joint quality of AgNWs under thermal excitation,the thermal welding process and atomic evolution behavior of AgNWs were investigated through a combination of in situ experimental and molecular dynamics simulations.The influence of processing time,temperature,and stress distribution due to spatial arrangement on nanojoints was systematically explored.What is more,the failure mechanisms and their atomic interface behavior of the nanojoints were also investigated.展开更多
A self-aligned process to fabricate a ＂metal-quantum dot-metal＂ structure is presented, based on an ＂electron beam lithography, thin film deposition and dry etching process＂. The sacrificial layers used can improv...A self-aligned process to fabricate a ＂metal-quantum dot-metal＂ structure is presented, based on an ＂electron beam lithography, thin film deposition and dry etching process＂. The sacrificial layers used can improve the lift-off process, and novel lithography layouts design can improve the mechanical strength of the fabricated nanostructures. The superiority of the self-aligned process includes low request for overlay accuracy, high compatibility with a variety of materials, and applicable to similar structure devices fabrication. Finally, a phase change memory with fully confined phase-change material node, with the length × width × height of 255 × 45 × 30 nm^3 was demonstrated.展开更多
This paper mainly focuses on solving the low yield problem for lateral phase change random access memory with a fully confined phase change material node. Improper over-etching and bad step-coverage of physical vapor ...This paper mainly focuses on solving the low yield problem for lateral phase change random access memory with a fully confined phase change material node. Improper over-etching and bad step-coverage of physical vapor deposition were the main reasons for the poor contact quality, which leads to the low yield problem. Process improvement was carried out to better control over-etching within 10 nm. Atomic layer deposition process was used to replace physical vapor deposition to guarantee good step coverage. Contrasting cross-sectional photos taken by scanning electron microscopy showed great improvement in contact quality. The atom layer deposition process was demonstrated to have good prospects in nano-contact for phase change memory application.展开更多
基金Supported by the National Natural Science Foundation of China under Grant No 11374058
文摘Current-voltage electrical characteristics of Er silicide/Si（001） nanocontacts are measured in situ in a scanning tunneling microscopy system. Introduced as a new technique to suppress surface leakage conduction on Si（001）,a silver wetting layer is evaporated onto the substrate surface kept at room temperature with Er Si2 nanoislands already existing. The effects of the silver layer on the current-voltage characteristics of nanocontacts are discussed.Our experimental results reveal that the silver layer at coverage of 0.4–0.7 monolayer can suppress effectively the current contribution from the surface conduction path. After the surface leakage path of nanocontacts is obstructed, the ideality factor and the Schottky barrier height are determined using the thermionic emission theory, about 2 and 0.5 eV, respectively. The approach adopted here could shed light on the intrinsic transport properties of metal-semiconductor nanocontacts.
文摘A "T" shaped micro-gap was fabricated by mechanical polishing between two Cu film electrodes on the surface of single-sided bonded copper.A nano-gap was then fabricated in the prepared micro-gap by resistance feedback controlled electroplating.Finally Ni 80 Fe 20 ferromagnetic nanocontacts of several sizes were fabricated in the prepared nano-gap by resistance feedback controlled electroplating.The magnetoresistance of each Ni 80 Fe 20 ferromagnetic nanocontact was not related to its size.Fabrication of the Ni 80 Fe 20 ferromagnetic nanocontacts in the nano-gap can reduce the contribution of magnetostriction to the magnetoresistance.The magnetoresistance values of the Ni 80 Fe 20 ferromagnetic nanocontacts were as high as those of the Ni ferromagnetic nanocontacts.This implies that the contribution of magnetostriction to the ballistic magnetoresistance of the ferromagnetic nanocontacts can be neglected.The ferromagnetic nanocontacts fabricated in this study,and in other cases,have two anisotropic interfaces on the sides of the nanocontacts.However,the magnetic field can alter the contribution of the interaction between the two anisotropic interfaces to the ballistic magnetoresistance of the ferromagnetic nanocontacts,and this effect can not be ruled out yet.
基金supported by National Natural Science Foundation of China(Grant Nos.52022078 and 51875450)Shaanxi Provincial Key Research and Development Program(Grant No.2021ZDLGY10-02)the fund of the State Key Laboratory of Solidification Processing in NPU,(Grant No.SKLSP202203)。
文摘Ag nanowires(AgNWs)have shown great application value in the field of flexible electronics due to their excellent optical and electrical properties,and the quality of its joints of AgNWs in the thin film network directly plays a key role in its performance.In order to further improve the joint quality of AgNWs under thermal excitation,the thermal welding process and atomic evolution behavior of AgNWs were investigated through a combination of in situ experimental and molecular dynamics simulations.The influence of processing time,temperature,and stress distribution due to spatial arrangement on nanojoints was systematically explored.What is more,the failure mechanisms and their atomic interface behavior of the nanojoints were also investigated.
基金supported by the National Basic Research Program of China(No.2011CB922103)the National Natural Science Foundation of China(Nos.61376420,61404126,A040203)
文摘A self-aligned process to fabricate a ＂metal-quantum dot-metal＂ structure is presented, based on an ＂electron beam lithography, thin film deposition and dry etching process＂. The sacrificial layers used can improve the lift-off process, and novel lithography layouts design can improve the mechanical strength of the fabricated nanostructures. The superiority of the self-aligned process includes low request for overlay accuracy, high compatibility with a variety of materials, and applicable to similar structure devices fabrication. Finally, a phase change memory with fully confined phase-change material node, with the length × width × height of 255 × 45 × 30 nm^3 was demonstrated.
基金supported by the National Basic Research Program of China(No.2011CB922103)the National Natural Science Foundation of China(Nos.61376420,61404126,A040203)the Science and Technology Project of Shenzhen(No.JCYJ20140509172609175)
文摘This paper mainly focuses on solving the low yield problem for lateral phase change random access memory with a fully confined phase change material node. Improper over-etching and bad step-coverage of physical vapor deposition were the main reasons for the poor contact quality, which leads to the low yield problem. Process improvement was carried out to better control over-etching within 10 nm. Atomic layer deposition process was used to replace physical vapor deposition to guarantee good step coverage. Contrasting cross-sectional photos taken by scanning electron microscopy showed great improvement in contact quality. The atom layer deposition process was demonstrated to have good prospects in nano-contact for phase change memory application.
