柔性非晶InGaZnO薄膜晶体管栅绝缘层的研究
|
摘要
采用磁控溅射方法,在聚酰亚胺薄膜上室温制备了非晶铟镓锌氧(a-IGZO)柔性薄膜晶体管(TFT)。其中,栅绝缘层选择了不同厚度比例的氧化硅(SiO_x)与氧化坦(TaO_x)薄膜的搭配,对比研究了不同栅绝缘层结构的薄膜特性以及所对应的柔性TFT器件的操作特性和偏压稳定性。实验结果表明,TaO_x的成膜速率明显高于SiO_x;随着TaO_x所占比例的增加,栅绝缘层表面粗糙度降低,介电常数显著提高。以300nm厚TaO_x搭配300nm厚SiO_x为例,栅绝缘层相对介电常数可以达到10,对应的a-IGZOTFT表现出了更高的的开态电流和更低的阈值电压,但是器件漏电流略有增加,正偏压稳定性也会有所下降。
We experimentally addressed the influence of the thickness-ratio of SiO_x/TaO_xin the gate insulators( GI) on the properties of the flexible amorphous InGaZnO thin film transistors( a-IGZO TFTs),fabricated at room temperature by magnetron sputtering on polyimide( PI) substrate. The preliminary results show that when it comes to the performance and bias-stress stability of TFTs,the SiO_x/TaO_xlayers outperformed the conventional SiO_xlayer. To be specific,the TaO_xlayer grew much faster than the SiO_xlayer; as the TaO_xthickness increased,the GI dielectric constant increased,accompanied by the decrease of GI surface roughness. For instance,the 300 nm SiO_xand 300 nm TaO_xlayers increased the relative GI dielectric constant up to 10,resulting in a larger on-current,a lower threshold voltage,a little smaller off-current but a bit worse bias-stress stability of the corresponding a-IGZO TFTs.
We experimentally addressed the influence of the thickness-ratio of SiO_x/TaO_xin the gate insulators( GI) on the properties of the flexible amorphous InGaZnO thin film transistors( a-IGZO TFTs),fabricated at room temperature by magnetron sputtering on polyimide( PI) substrate. The preliminary results show that when it comes to the performance and bias-stress stability of TFTs,the SiO_x/TaO_xlayers outperformed the conventional SiO_xlayer. To be specific,the TaO_xlayer grew much faster than the SiO_xlayer; as the TaO_xthickness increased,the GI dielectric constant increased,accompanied by the decrease of GI surface roughness. For instance,the 300 nm SiO_xand 300 nm TaO_xlayers increased the relative GI dielectric constant up to 10,resulting in a larger on-current,a lower threshold voltage,a little smaller off-current but a bit worse bias-stress stability of the corresponding a-IGZO TFTs.
引文
[1]Heremans P,Tripathi A K,De J d M A,et al.Mechanical and Electronic Properties of Thin-Film Transistors on Plastic,and Their Integration in Flexible Electronic Applications[J].Advanced Materials,2016,28(22):4266-4282
[2]Chow M J,Fomani A A,Moradi M,et al.Effects of Mechanical Strain on Amorphous Silicon Thin-Film Transistor Electrical Stability[J].Applied Physics Letters,2013,102(23):597-496
[3]Lee C Y,Chang C,Shih W P,et al.Wet Etching Rates of In Ga Zn O for the Fabrication of Transparent Thin-Film Transistors on Plastic Substrates[J].Thin Solid Films,2010,518(14):3992-3998
[4]刘金刚,倪洪江,郭远征,等.柔性显示器件用聚酰亚胺基板的研究与应用进展[J].精细与专用化学品,2014,22(9):1-6
[5]Park J S,Kim T W,Stryakhilev D,et al.Flexible Full Color Organic Light-Emitting Diode Display on Polyimide Plastic Substrate Driven by Amorphous Indium Gallium Zinc Oxide Thin-Film Transistors[J].Applied Physics Letters,2009,95(1):013503-013503-3
[6]Hatano K,Chida A,Okano T,et al.3.4-inch Full-Color QHD AMOLED Display using Large-Size Flexible Substrate with Highly Reliable OS-FETs[J].Sid Symposium Digest of Technical Papers,2011,42(1):498-500
[7]Lai H C,Tzeng B J,Pei Z,et al.Ultra-flexible Amorphous Indium-Gallium-Zinc Oxide(a-IGZO)Thin Film Transistor[J].Sid Symposium Digest of Technical Papers,2012,43(1):764-767
[8]Yang S,Bak J Y,Yoon S M,et al.Low-Temperature Processed Flexible In-Ga-Zn-O Thin-Film Transistors Exhibiting High Electrical Performance[J].IEEE Electron Device Letters,2011,32(12):1692-1694
[9]Cherenack K H,Münzenrieder N S,Tr?ster G.Impact of Mechanical Bending on Zn O and IGZO Thin-Film Transistors[J].IEEE Electron Device Letters,2010,31(11):1254-1256
[10]Geng D,Kim H M,Mativenga M,et al.High Resolution Flexible AMOLED with Integrated Gate-Driver using Bulk-Accumulation a-IGZO TFTs[J].Sid Symposium Digest of Technical Papers,2015,46(1):423-426
[11]Shi Junfei,Dong Chengyuan,Dai Wenjun,et al.The Influence of RF Power on the Electrical Properties of Sputtered Amorphous In-Ga-Zn-O Thin Films and Devices[J].Journal of Semiconductors,2013,34(8):084003-084003-5
[12]Wagner S,Gleskova H,Cheng I,et al.Flexible Flat Panel Displays[M].USA:John Wiley&Sons,2005:263-283
[13]Lee J S,Chang S,Koo S M,et al.High-Performance a-IGZO TFT With Zr O2Gate Dielectric Fabricated at Room Temperature[J].IEEE Electron Device Letters,2010,31(3):225-227
[14]Hsu H H,Chang C Y,Cheng C H.A Flexible IGZO Thin-Film Transistor With Stacked Ti O2-Based Dielectrics Fabricated at Room Temperature[J].IEEE Electron Device Letters,2013,34(6):768-770
[15]董承远.薄膜晶体管原理及应用[M].北京:清华大学出版社,2016
[16]Chiu C J,Chang S P,Chang S J.High-Performance aIGZO Thin-Film Transistor Using Ta2O5Gate Dielectric[J].IEEE Electron Device Letters,2010,31(11):1245-1247
[17]Andreoni W,Pignedoli C A.Ta2O5polymorphs:Structural Motifs and Dielectric Constant from First Principles[J].Applied Physics Letters,2010,96(6):54
[18]Cava R J,Krajewski J J,Peck W F,et al.Dielectric Properties of Ta2O5-Si O2Polycrystalline Ceramics[J].Journal of Applied Physics,1996,80(4):2346-2348
[19]Bartic C,Jansen H,Campitelli A,et al.Ta2O5as Gate Dielectric Material for Low-Voltage Organic Thin-Film Transistors[J].Organic Electronics,2002,3(2):65-72
[2]Chow M J,Fomani A A,Moradi M,et al.Effects of Mechanical Strain on Amorphous Silicon Thin-Film Transistor Electrical Stability[J].Applied Physics Letters,2013,102(23):597-496
[3]Lee C Y,Chang C,Shih W P,et al.Wet Etching Rates of In Ga Zn O for the Fabrication of Transparent Thin-Film Transistors on Plastic Substrates[J].Thin Solid Films,2010,518(14):3992-3998
[4]刘金刚,倪洪江,郭远征,等.柔性显示器件用聚酰亚胺基板的研究与应用进展[J].精细与专用化学品,2014,22(9):1-6
[5]Park J S,Kim T W,Stryakhilev D,et al.Flexible Full Color Organic Light-Emitting Diode Display on Polyimide Plastic Substrate Driven by Amorphous Indium Gallium Zinc Oxide Thin-Film Transistors[J].Applied Physics Letters,2009,95(1):013503-013503-3
[6]Hatano K,Chida A,Okano T,et al.3.4-inch Full-Color QHD AMOLED Display using Large-Size Flexible Substrate with Highly Reliable OS-FETs[J].Sid Symposium Digest of Technical Papers,2011,42(1):498-500
[7]Lai H C,Tzeng B J,Pei Z,et al.Ultra-flexible Amorphous Indium-Gallium-Zinc Oxide(a-IGZO)Thin Film Transistor[J].Sid Symposium Digest of Technical Papers,2012,43(1):764-767
[8]Yang S,Bak J Y,Yoon S M,et al.Low-Temperature Processed Flexible In-Ga-Zn-O Thin-Film Transistors Exhibiting High Electrical Performance[J].IEEE Electron Device Letters,2011,32(12):1692-1694
[9]Cherenack K H,Münzenrieder N S,Tr?ster G.Impact of Mechanical Bending on Zn O and IGZO Thin-Film Transistors[J].IEEE Electron Device Letters,2010,31(11):1254-1256
[10]Geng D,Kim H M,Mativenga M,et al.High Resolution Flexible AMOLED with Integrated Gate-Driver using Bulk-Accumulation a-IGZO TFTs[J].Sid Symposium Digest of Technical Papers,2015,46(1):423-426
[11]Shi Junfei,Dong Chengyuan,Dai Wenjun,et al.The Influence of RF Power on the Electrical Properties of Sputtered Amorphous In-Ga-Zn-O Thin Films and Devices[J].Journal of Semiconductors,2013,34(8):084003-084003-5
[12]Wagner S,Gleskova H,Cheng I,et al.Flexible Flat Panel Displays[M].USA:John Wiley&Sons,2005:263-283
[13]Lee J S,Chang S,Koo S M,et al.High-Performance a-IGZO TFT With Zr O2Gate Dielectric Fabricated at Room Temperature[J].IEEE Electron Device Letters,2010,31(3):225-227
[14]Hsu H H,Chang C Y,Cheng C H.A Flexible IGZO Thin-Film Transistor With Stacked Ti O2-Based Dielectrics Fabricated at Room Temperature[J].IEEE Electron Device Letters,2013,34(6):768-770
[15]董承远.薄膜晶体管原理及应用[M].北京:清华大学出版社,2016
[16]Chiu C J,Chang S P,Chang S J.High-Performance aIGZO Thin-Film Transistor Using Ta2O5Gate Dielectric[J].IEEE Electron Device Letters,2010,31(11):1245-1247
[17]Andreoni W,Pignedoli C A.Ta2O5polymorphs:Structural Motifs and Dielectric Constant from First Principles[J].Applied Physics Letters,2010,96(6):54
[18]Cava R J,Krajewski J J,Peck W F,et al.Dielectric Properties of Ta2O5-Si O2Polycrystalline Ceramics[J].Journal of Applied Physics,1996,80(4):2346-2348
[19]Bartic C,Jansen H,Campitelli A,et al.Ta2O5as Gate Dielectric Material for Low-Voltage Organic Thin-Film Transistors[J].Organic Electronics,2002,3(2):65-72