技術文章
TECHNICAL ARTICLES隨著電子信息產業的高速發展,集成電路的需求出現了井噴式的增長。使得掩膜的需求急劇增加,目前制作掩膜的主要技術是電子束直寫,但該制作效率非常低下,并且成本也不容小覷,在這種背景下人們把目光轉移到了無掩膜光刻技術。
英國Durham Magneto Optics公司致力于研發小型臺式無掩膜光刻直寫系統(MicroWriter ML3),為微流控、MEMS、半導體、自旋電子學等研究域提供方便的微加工方案。傳統的光刻工藝中所使用的鉻玻璃掩膜板需要由業供應商提供,但是在研發過程中,掩膜板的設計通常需要根據實際情況多次改變。無掩膜光刻技術通過以軟件設計電子掩膜板的方法,克服了這問題。與通過物理掩膜板進行光照的傳統工藝不同,激光直寫是通過電腦控制DMD微鏡矩陣開關,經過光學系統調制,在光刻膠上直接曝光繪出所要的圖案。同時其還具備結構緊湊(70cm X 70cm X 70cm)、高直寫速度,高分辨率(XY:<1 um)的點。采用集成化設計,全自動控制,可靠性高,操作簡便。
() SMALL: 高性能的具備實際應用前景的晶圓MoS2晶體管
原子層的過渡金屬二硫化物(TMD)被認為是下代半導體器件的重要研究熱點。然而,目前大部分的器件都是基于層間剝離來獲取金屬硫化物層,這樣只能實現微米的制備。在本文中,作者提出種用化學氣相沉積(CVD)制備多層MoS2薄層,進而改善所制備器件的相關性能。采用四探針法測量證明接觸電阻降低個數量。進步,基于該法制備的連續大面積MoS2薄層,采用小型無掩膜光刻直寫系統(MicroWriter ML3)構筑了頂柵場效應晶體管(FET)陣列。研究表明其閾值電壓和場效應遷移率均有明顯的提升,平均遷移率可以達到70 cm2V-1s-1,可與層間剝離法制備的MoS2 FET結果相媲美。本工作創制了種規模化制備二維TMD功能器件和集成電路應用的有效方法。
圖1. (a-e) 用CVD法制備大面積多層MoS2的原理示意及形貌結果。(g, h, i, j) 單層MoS2邊界及多層MoS2片層島的AFM測試結果,拉曼譜及光致發光譜結果
圖2. 用無掩膜激光直寫系統(MicroWriter)在MoS2薄層上制備的多探針(二探針/四探針)測量系統,以及在不同條件下測量的接觸電阻和遷移率結果。證明所制多層MoS2的平均遷移率可以達到70 cm2V-1s-1
圖3. 用無掩膜光刻直寫系統(MicroWriter)制備的大面積規模MoS2 FET陣列,及其場效應遷移率和閾值電壓的分布性測量結果,證明該規模MoS2 FET陣列具備異且穩定的均性
(二) Adv. Funct. Mater.: 二維超薄非層狀Cr2S3納米片的氣相沉積制備與拉曼表征
二維磁性材料在自旋磁電子學域展現出巨大的應用價值,但是大部分已報道的磁性材料都是具備范德瓦爾斯作用的層狀結構,這種結構可以通過簡單的剝離方法獲得。與之相反,非層狀超薄磁性材料制備工藝復雜且非常,其中Cr2S3就是種典型的反鐵磁性非層狀材料。在本文中,作者通過改進化學氣相沉積(CVD)方法,成功制備出超薄的非層狀Cr2S3納米片(厚度薄可達2.5 nm),并深入研究了材料的Raman振動模式及熱導性,同時用無掩膜激光直寫系統(MicroWriter)在材料表面制備電結構,測試系列相關電學性。
圖4. 超薄Cr2S3納米片的制備流程示意圖及其光學形貌和AFM表面形貌
圖5. (a) SiO2/Si基底表面的Cr2S3納米片的AFM表面形貌,(b) 用MicroWriter在Cr2S3納米片上制備測量電,測量材料隨溫度變化的I-V性曲線,(c) 隨溫度變化的電導率測量結果及擬合曲線比較
(三) Adv. Optical Mater.: 通過對全無機三鹵鈣鈦礦納米晶的調控,制備出性能良、空氣穩定及可調諧的單分子層MoS2基混合光探測器件
全無機三鹵鈣鈦礦納米晶在過去的數年間受到廣泛的關注,基于其異的光物理性和環境穩定性,該種新材料在混合光電器件研究域備受關注。在本文中,作者制備出種單層MoS2與三鹵鈣鈦礦納米晶結合的異質結光電器件,通過調節鈣鈦礦膠體濃度和表面配體量,進而實現調控該異質結器件的光電性。在空氣環境中,該異質結光電器件的光響應可達6.4×105 mA/W,同時表現出異的熱穩定性和工作穩定性。
圖6. CsPbBr3 PNC/monolayer MoS2異質結光電器件的物理結構及工作機理示意
圖7. 不同溶液濃度的鈣鈦礦前驅體所制備得到的異質結器件的光電性比較
在該異質結的制備過程中,需要在所制備的單層MoS2表面制備Cr/Au電,用小型無掩膜光刻直寫系統(MicroWriter),可以將所設計的電圖案直接在MoS2層表面進行曝光,避免由與制備圖形掩膜版所帶來的時間及工藝成本,同時用MicroWriter所有的虛擬掩膜對準(Visual Mask Alignment, VMA)功能,可以在實際圖形曝光過程中,準確地找到MoS2目標位置,這樣大大地提高了實驗設計和實施的靈活性。
圖8. CsPbBr3 PNC/monolayer MoS2異質結光電器件的制備流程,紅色框所示為用無掩膜激光直寫系統(MicroWriter)所制備電結構示意
圖9. (左)用MicroWriter制備的MoS2基器件的I-V性曲線,其中所示單層MoS2形貌及表面電;(右)MicroWriter虛擬掩膜功能(VMA)結果示意
2019年:
[1] Leonardi F, Zhang Q, Kim Y H, et al. Solution-sheared thin films of a donor-acceptor random copolymer/polystyrene blend as active material in field-effect transistors[J]. Materials Science in Semiconductor Processing, 2019, 93: 105-110.
[2] Mortet V, Drbohlavova L, Lambert N, et al. Conductivity of boron-doped diamond at high electrical field[J]. Diamond and Related Materials, 2019, 98: 107476.
[3] Armistead F J, De Pablo J G, Gadêlha H, et al. Cells Under Stress: An Inertial-Shear Microfluidic Determination of Cell Behavior[J]. Biophysical journal, 2019, 116(6): 1127-1135.
[4] Salzillo T, Campos A, Mas-Torrent M. Solution-processed thin films of a charge transfer complex for ambipolar field-effect transistors[J]. Journal of Materials Chemistry C, 2019, 7(33): 10257-10263.
[5] Chen H, Liu G, Zhang S, et al. Fundus-simulating phantom for calibration of retinal vessel oximetry devices[J]. Applied optics, 2019, 58(14): 3877-3885.
[6] Zhang S, Xu H, Liao F, et al. Wafer-scale transferred multilayer MoS2 for high performance field effect transistors[J]. Nanotechnology, 2019, 30(17): 174002.
[7] Martin E L, Bryan M T, Pagliara S, et al. Advanced Processing of Micropatterned Elasto-Magnetic Membranes[J]. IEEE Transactions on Magnetics, 2019.
[8] Liu J, Singh A, Llandro J, et al. A low-temperature Kerr effect microscope for the simultaneous magneto-optic and magneto-transport study of magnetic topological insulators[J]. Measurement Science and Technology, 2019.
[9] Ye K, Liu L, Liu Y, et al. Lateral Bilayer MoS2–WS2 Heterostructure Photodetectors with High Responsivity and Detectivity[J]. Advanced Optical Materials, 2019: 1900815.
[10] Gilboa T, Zvuloni E, Zrehen A, et al. Automated, Ultra‐Fast Laser‐Drilling of Nanometer Scale Pores and Nanopore Arrays in Aqueous Solutions[J]. Advanced Functional Materials, 2019: 1900642.
[11] You H, Zhuo Z, Lu X, et al. 1T′-MoTe2-Based On-Chip Electrocatalytic Microdevice: A Platform to Unravel Oxidation-Dependent Electrocatalysis[J]. CCS Chemistry, 2019: 396-406.
[12] Fan X, Wei G, Lin X, et al. Phase-Change Based Interlayer Exchange Coupling Control[J]. arXiv preprint arXiv:1907.10784, 2019.
[13]Zhang Q, Leonardi F, Pfattner R, et al. A Solid‐State Aqueous Electrolyte‐Gated Field‐Effect Transistor as a Low‐Voltage Operation Pressure‐Sensitive Platform[J]. Advanced Materials Interfaces, 2019: 1900719.
[14] Yang R, Liu L, Feng S, et al. One-Step Growth of Spatially Graded Mo1-xWxS2 Monolayer with Wide Span in Composition (from x= 0 to 1) at Large Scale[J]. ACS applied materials & interfaces, 2019.
[15] Zhang L, Shen S, Li M, et al. Strategies for Air‐Stable and Tunable Monolayer MoS2‐Based Hybrid Photodetectors with High Performance by Regulating the Fully Inorganic Trihalide Perovskite Nanocrystals[J]. Advanced Optical Materials, 2019: 1801744.
[16] Zhou S, Wang R, Han J, et al. Ultrathin Non‐van der Waals Magnetic Rhombohedral Cr2S3: Space‐Confined Chemical Vapor Deposition Synthesis and Raman Scattering Investigation[J]. Advanced Functional Materials, 2019, 29(3): 1805880.
[17] Chen Y, Casals B, Sanchez F, et al. Solid-State Synapses Modulated by Wavelength-Sensitive Temporal Correlations in Optic Sensory Inputs[J]. ACS Applied Electronic Materials, 2019.
[18] Gu Y, Oliferenko S. Cellular geometry scaling ensures robust division site positioning[J]. Nature communications, 2019, 10(1): 268.
2018年:
[1] Wei G, Lin X, Si Z, et al. Optical control of magnetism in NiFe/VO2 heterostructures[J]. arXiv preprint arXiv:1805.02453, 2018.
[2] Davydova M, Taylor A, Hubík P, et al. Characteristics of zirconium and niobium contacts on boron-doped diamond[J]. Diamond and Related Materials, 2018, 83: 184-189.
[3] Campos A, Riera-Galindo S, Puigdollers J, et al. Reduction of charge traps and stability enhancement in solution-processed organic field-effect transistors based on a blended n-type semiconductor[J]. ACS applied materials & interfaces, 2018, 10(18): 15952-15961.
[4] Jia Z, Hu W, Xiang J, et al. Grain wall boundaries in centimeter-scale continuous monolayer WS2 film grown by chemical vapor deposition[J]. Nanotechnology, 2018, 29(25): 255705.
[5]Tarn M D, Sikora S N F, Porter G C E, et al. The study of atmospheric ice-nucleating particles via microfluidically generated droplets[J]. Microfluidics and nanofluidics, 2018, 22(5): 52.
[6] Jin B, Huang P, Zhang Q, et al. Self‐Limited Epitaxial Growth of Ultrathin Nonlayered CdS Flakes for High‐Performance Photodetectors[J]. Advanced Functional Materials, 2018, 28(20): 1800181.
[7] Vallès F, Palau A, Rouco V, et al. Angular flux creep contributions in YBa2Cu3O7−δ nanocomposites from electrical transport measurements[J]. Scientific reports, 2018, 8(1): 5924.
[8] L?pez-Mir L, Frontera C, Aramberri H, et al. Anisotropic sensor and memory device with a ferromagnetic tunnel barrier as the only magnetic element[J]. Scientific reports, 2018, 8(1): 861.
[9] Xu H, Zhang H, Guo Z, et al. High‐Performance Wafer‐Scale MoS2 Transistors toward Practical Application[J]. Small, 2018, 14(48): 1803465.