The chemical mechanical polishing/planarization（CMP） performance of an inhibitor-free alkaline copper slurry is investigated.The results of the Cu dissolution rate（DR） and the polish rate（PR） show that the alkal...The chemical mechanical polishing/planarization（CMP） performance of an inhibitor-free alkaline copper slurry is investigated.The results of the Cu dissolution rate（DR） and the polish rate（PR） show that the alkaline slurry without inhibitors has a relatively high copper removal rate and considerable dissolution rate.Although the slurry with inhibitors has a somewhat low DR,the copper removal rate was significantly reduced due to the addition of inhibitors（Benzotriazole,BTA）.The results obtained from pattern wafers show that the alkaline slurry without inhibitors has a better planarization efficacy;it can planarize the uneven patterned surface during the excess copper removal.These results indicate that the proposed inhibitor-free copper slurry has a considerable planarization capability for CMP of Cu pattern wafers,it can be applied in the first step of Cu CMP for copper bulk removal.展开更多
InGaN MQW LEDs, grown by metal-organic chemical vapor deposition (MOCVD) on Si(111) substrates, were successfully bonded and transferred onto new Si substrate. After chemical etching Si(111) substrate and inductively ...InGaN MQW LEDs, grown by metal-organic chemical vapor deposition (MOCVD) on Si(111) substrates, were successfully bonded and transferred onto new Si substrate. After chemical etching Si(111) substrate and inductively coupled plasma (ICP) etching the transferred LED film to Si-doped layer, a vertical structure GaN blue LEDs were then fabricated. The characteristics of the lateral structure LED (grown on Si) and the vertical structure LED (bonded on Si) were investigated. It shows the performance of ver- tical structure LEDs had obviously been improved compared to the lateral structure LEDs and the tensile stress in GaN layer of vertical structure LEDs is smaller than that in lateral structure LEDs.展开更多
It is always a great challenge to bridge the nano-and macro-worlds in nanoscience,for instance,manufacturing uniform nanogratings on a whole wafer in seconds instead of hours even days.Here,we demonstrate a single-ste...It is always a great challenge to bridge the nano-and macro-worlds in nanoscience,for instance,manufacturing uniform nanogratings on a whole wafer in seconds instead of hours even days.Here,we demonstrate a single-step while extremely high-throughput femtosecond laser scanning technique to obtain wafer-scale,highly regular nanogratings on semiconductor-on-metal thin films.Our technique takes advantage of long-range surface plasmons-laser interference,which is regulated by a self-initiated seed.By controlling the scanning speed,two types of nanogratings are readily manufactured,which are produced by either oxidation or ablation.We achieve a record manufacturing speed(>1 cm^(2)s^(-1)),with tunable periodicity of∧<1μm.The fractional variation of their periodicity is evaluated to be as low as△∧/∧≈0.5%.Furthermore,by utilizing the semiconductor-on-metal film-endowed interference effects,an extremely high energy efficiency is achieved via suppressing light reflection during femtosecond laser nano-processing.As the fabricated nanogratings exhibit multi-functionality,we exemplify their practical applications in highly sensitive refractive index sensing,vivid structural colors,and durable superhydrophilicity.展开更多
Ever since discovery of graphene,two-dimensional(2D)materials become a new tool box for information technology.Among the 2D family,ultrathin bismuth(Bi)has attracted a great deal of attention in recent years due to it...Ever since discovery of graphene,two-dimensional(2D)materials become a new tool box for information technology.Among the 2D family,ultrathin bismuth(Bi)has attracted a great deal of attention in recent years due to its unique topological insulating properties and large magnetoresistance.However,the scalable synthesis of layered Bi ultrathin films is rarely been reported,which would greatly restrict further fundamental investigation and practical device development.Here,we demonstrate the direct growth of homogeneous and centimeter-scale layered Bi films by pulsed laser deposition(PLD)technique.The as-grown Bi film exhibits high-purity phase and good crystallinity.In addition,both(111)and(110)-oriented Bi films can be synthesized by precisely controlling the processing temperature.The characterization of optical properties shows a thickness dependent band gaps(0.075-0.2 eV).Moreover,Bi thin-film-based field-effect transistors have been demonstrated,exhibiting a large carrier mobility of 220 cm2 V−1 s−1.Our work suggests that the PLD-grown Bi films would hold the potential to develop spintronic applications,electronic and optoelectronic devices used for information science and technology.展开更多
介绍了低介质损耗共面波导(CPW)传输线电容测量方法中的反射系数测量及线电容外推测量技术,成功提取了商用校准基片101-190C上传输线的线电容。根据线电容算法模型,以校准件及矢网内部接收机动态幅相精度不理想作为误差来源,采用蒙特卡...介绍了低介质损耗共面波导(CPW)传输线电容测量方法中的反射系数测量及线电容外推测量技术,成功提取了商用校准基片101-190C上传输线的线电容。根据线电容算法模型,以校准件及矢网内部接收机动态幅相精度不理想作为误差来源,采用蒙特卡罗仿真对线电容测量结果的不确定度进行了评定。最后将线电容用于多线TRL校准,与NIST标定结果更接近,在40 GHz频率范围内,反射系数模值相差小于±0.02,传输幅度模值相差小于±0.05 d B,传输相位相差小于±1°。展开更多
As the large single-crystalline silicon wafers have revolutionized many industries including electronics and solar cells, it is envisioned that the availability of large single-crystalline perovskite crystals and wafe...As the large single-crystalline silicon wafers have revolutionized many industries including electronics and solar cells, it is envisioned that the availability of large single-crystalline perovskite crystals and wafers will revolutionize its broad applications in photovoltaics, optoelectronics, lasers, photodetectors, light emitting diodes(LEDs), etc. Here we report a method to grow large single-crystalline perovskites including single-halide crystals: CH3NH3PbX3(X=I, Br, Cl), and dual-halide ones:CH3NH3Pb(ClxBr1.x)3 and CH3NH3Pb(BrxI1.x)3, with the largest crystal being 120 mm in length. Meanwhile, we have advanced a process to slice the large perovskite crystals into thin wafers. It is found that the wafers exhibit remarkable features:(1)its trap-state density is a million times smaller than that in the microcrystalline perovskite thin films(MPTF);(2) its carrier mobility is 410 times higher than its most popular organic counterpart P3HT;(3) its optical absorption is expanded to as high as910 nm comparing to 797 nm for the MPTF;(4) while MPTF decomposes at 150 °C, the wafer is stable at high temperature up to270 °C;(5) when exposed to high humidity(75% RH), MPTF decomposes in 5 h while the wafer shows no change for overnight;(6) its photocurrent response is 250 times higher than its MPTF counterpart. A few electronic devices have been fabricated using the crystalline wafers. Among them, the Hall test gives low carrier concentration with high mobility. The trap-state density is measured much lower than common semiconductors. Moreover, the large SC-wafer is found particularly useful for mass production of integrated circuits. By adjusting the halide composition, both the optical absorption and the light emission can be fine-tuned across the entire visible spectrum from 400 nm to 800 nm. It is envisioned that a range of visible lasers and LEDs may be developed using the dual-halide perovskites. With fewer trap states, high mobility, broader absorption, and humidity resistance, it is expected that solar cells wi展开更多
基金supported by the Major National Science and Technology Special Projects,China(No.2009ZX02308)the Tianjin Natural Science Foundation of China(No.lOJCZDJC 15500)+1 种基金the National Natural Science Foundation of China(No.10676008)the Fund Project of Hebei Provincial Department of Education,China(No.2011128)
文摘The chemical mechanical polishing/planarization（CMP） performance of an inhibitor-free alkaline copper slurry is investigated.The results of the Cu dissolution rate（DR） and the polish rate（PR） show that the alkaline slurry without inhibitors has a relatively high copper removal rate and considerable dissolution rate.Although the slurry with inhibitors has a somewhat low DR,the copper removal rate was significantly reduced due to the addition of inhibitors（Benzotriazole,BTA）.The results obtained from pattern wafers show that the alkaline slurry without inhibitors has a better planarization efficacy;it can planarize the uneven patterned surface during the excess copper removal.These results indicate that the proposed inhibitor-free copper slurry has a considerable planarization capability for CMP of Cu pattern wafers,it can be applied in the first step of Cu CMP for copper bulk removal.
基金supported by the 863 Project(Grant Nos.2005AA311010 and 2003AA302160)the Electronic Development Fund of Information Industry in China(Grant Nos.(2004)125 and(2004)479)Nanchang University Science Foundation.
文摘InGaN MQW LEDs, grown by metal-organic chemical vapor deposition (MOCVD) on Si(111) substrates, were successfully bonded and transferred onto new Si substrate. After chemical etching Si(111) substrate and inductively coupled plasma (ICP) etching the transferred LED film to Si-doped layer, a vertical structure GaN blue LEDs were then fabricated. The characteristics of the lateral structure LED (grown on Si) and the vertical structure LED (bonded on Si) were investigated. It shows the performance of ver- tical structure LEDs had obviously been improved compared to the lateral structure LEDs and the tensile stress in GaN layer of vertical structure LEDs is smaller than that in lateral structure LEDs.
基金supported by the National Key Research and Development Program of China(2017YF A0205700)the National Natural Science Foundation of China(No.61927820,No.12004314,No 62105269)+3 种基金supported by Zhejiang Province Selected Funding for Postdoctoral Research Projects(ZJ2021044)China Potdoctoral Scence Foundation(2021M702916)supported by the open projet program of Wuhan National Laboratory for optoelectronics No.2020WNLOKF004Zhejiang Provinial Natural Science Foundation of China under Grant No.Q21A040010.
文摘It is always a great challenge to bridge the nano-and macro-worlds in nanoscience,for instance,manufacturing uniform nanogratings on a whole wafer in seconds instead of hours even days.Here,we demonstrate a single-step while extremely high-throughput femtosecond laser scanning technique to obtain wafer-scale,highly regular nanogratings on semiconductor-on-metal thin films.Our technique takes advantage of long-range surface plasmons-laser interference,which is regulated by a self-initiated seed.By controlling the scanning speed,two types of nanogratings are readily manufactured,which are produced by either oxidation or ablation.We achieve a record manufacturing speed(>1 cm^(2)s^(-1)),with tunable periodicity of∧<1μm.The fractional variation of their periodicity is evaluated to be as low as△∧/∧≈0.5%.Furthermore,by utilizing the semiconductor-on-metal film-endowed interference effects,an extremely high energy efficiency is achieved via suppressing light reflection during femtosecond laser nano-processing.As the fabricated nanogratings exhibit multi-functionality,we exemplify their practical applications in highly sensitive refractive index sensing,vivid structural colors,and durable superhydrophilicity.
基金This work was supported by the grants from Research Grants Council of Hong Kong CRF No.C7036-17WGRF No.PolyU 153033/17PPolyU Grant No.G-UABC.
文摘Ever since discovery of graphene,two-dimensional(2D)materials become a new tool box for information technology.Among the 2D family,ultrathin bismuth(Bi)has attracted a great deal of attention in recent years due to its unique topological insulating properties and large magnetoresistance.However,the scalable synthesis of layered Bi ultrathin films is rarely been reported,which would greatly restrict further fundamental investigation and practical device development.Here,we demonstrate the direct growth of homogeneous and centimeter-scale layered Bi films by pulsed laser deposition(PLD)technique.The as-grown Bi film exhibits high-purity phase and good crystallinity.In addition,both(111)and(110)-oriented Bi films can be synthesized by precisely controlling the processing temperature.The characterization of optical properties shows a thickness dependent band gaps(0.075-0.2 eV).Moreover,Bi thin-film-based field-effect transistors have been demonstrated,exhibiting a large carrier mobility of 220 cm2 V−1 s−1.Our work suggests that the PLD-grown Bi films would hold the potential to develop spintronic applications,electronic and optoelectronic devices used for information science and technology.
文摘介绍了低介质损耗共面波导(CPW)传输线电容测量方法中的反射系数测量及线电容外推测量技术,成功提取了商用校准基片101-190C上传输线的线电容。根据线电容算法模型,以校准件及矢网内部接收机动态幅相精度不理想作为误差来源,采用蒙特卡罗仿真对线电容测量结果的不确定度进行了评定。最后将线电容用于多线TRL校准,与NIST标定结果更接近,在40 GHz频率范围内,反射系数模值相差小于±0.02,传输幅度模值相差小于±0.05 d B,传输相位相差小于±1°。
基金supported by the National Key Research Project MOST (2016YFA0202400)the National Natural Science Foundation of China (61604090, 61604091, 61674098)+4 种基金National University Research Fund (GK261001009, GK201603107)the Changjiang Scholar and Innovative Research Team (IRT_14R33)the 111 Project (B14041)the Chinese National 1000-talent-plan Program (1110010341)the Innovation Funds of Graduate Programs, SNNU (2015CXS047)
文摘As the large single-crystalline silicon wafers have revolutionized many industries including electronics and solar cells, it is envisioned that the availability of large single-crystalline perovskite crystals and wafers will revolutionize its broad applications in photovoltaics, optoelectronics, lasers, photodetectors, light emitting diodes(LEDs), etc. Here we report a method to grow large single-crystalline perovskites including single-halide crystals: CH3NH3PbX3(X=I, Br, Cl), and dual-halide ones:CH3NH3Pb(ClxBr1.x)3 and CH3NH3Pb(BrxI1.x)3, with the largest crystal being 120 mm in length. Meanwhile, we have advanced a process to slice the large perovskite crystals into thin wafers. It is found that the wafers exhibit remarkable features:(1)its trap-state density is a million times smaller than that in the microcrystalline perovskite thin films(MPTF);(2) its carrier mobility is 410 times higher than its most popular organic counterpart P3HT;(3) its optical absorption is expanded to as high as910 nm comparing to 797 nm for the MPTF;(4) while MPTF decomposes at 150 °C, the wafer is stable at high temperature up to270 °C;(5) when exposed to high humidity(75% RH), MPTF decomposes in 5 h while the wafer shows no change for overnight;(6) its photocurrent response is 250 times higher than its MPTF counterpart. A few electronic devices have been fabricated using the crystalline wafers. Among them, the Hall test gives low carrier concentration with high mobility. The trap-state density is measured much lower than common semiconductors. Moreover, the large SC-wafer is found particularly useful for mass production of integrated circuits. By adjusting the halide composition, both the optical absorption and the light emission can be fine-tuned across the entire visible spectrum from 400 nm to 800 nm. It is envisioned that a range of visible lasers and LEDs may be developed using the dual-halide perovskites. With fewer trap states, high mobility, broader absorption, and humidity resistance, it is expected that solar cells wi
