52nd Annual Device Research Conference最新文献_第4页

Analysis of leakage currents in multiple gate poly-si thin film transistors for active matrix liquid crystal displays 有源矩阵液晶显示器用多栅多晶硅薄膜晶体管漏电流分析

52nd Annual Device Research Conference Pub Date : 1994-06-20 DOI: 10.1109/DRC.1994.1009412

M. Hack, I. Wu

{"title":"Analysis of leakage currents in multiple gate poly-si thin film transistors for active matrix liquid crystal displays","authors":"M. Hack, I. Wu","doi":"10.1109/DRC.1994.1009412","DOIUrl":"https://doi.org/10.1109/DRC.1994.1009412","url":null,"abstract":"In this paper we show good agreement between numerical simulations and experimental data of the electrical characteristics of multiple gate poly-crystalline silicon (poly-Si) thin film transistors (TFTs). We focus on leakage current, as this is the most critical TFT characteristic for pixel switches in high resolution active matrix liquid crystal displays (AMLCD). The minimum leakage current ( Imin) determines grey level performance, while the sharpness of the minimum determines the range of negative gate bias required to maintain leakages close to I m i n , Leakage currents in poly-Si TFTs have been shown to be caused by a high electric field tunneling mechanism at specific traps, probably associated with intra-grain defects [l]. Various strategies are currently being employed to reduce leakage currents, but multiple gate devices [2] are preferential on account of their ease of implementation. In multiple gate structures the gated regions are connected by heavily doped channel regions. Experimentally we show [3] that while NMOS multiple gate structures reduce I m i n , they do not reduce the slope of the leakage current increase with larger reverse gate biases, V, , . This result is contrary to initial expectations that multiple gate TFTs would reduce the slope of the reverse V, , leakage, as the drain bias (Vds) is divided between the gated regions, and as minority carriers generated in the drain high field region would recombine in the (or one of the) heavily doped channel region(s) without reaching the source. In this paper we demonstrate, for the first time, why multiple gate TFTs have the same leakage increase a t negative gate voltages as single gate TFTs. Leakage currents are simulated by adding a single tunneling trap with a temperature independent tunneling mechanism to an effective medium model [l]. With increasing reverse V, , the maximum channel electric field moves from the edge of the gated region (second) near the TFT drain to the drain edge of the gated region nearest to the source (first), causing the leakage current slope to be independent of the number of gates. Multiple gate structures lower Imin as the vds is divided between the different gated regions, reducing the peak channel electric field. The leakage of a double gate TFT a t Vds = 10 Volts is higher than that of a single gate device a t vds=Sv. The experimental data of the dependence of leakage on reverse V,, are in good agreement with the simulation results. Contour plots of the channel electric field for vds= 1OV in a double gate TFT show that for VgS above the value needed for minimum leakage current (Vgsmin) the highest field is near to the edge of the gated region nearest the device drain. Carrier concentration profiles show that few minority carriers generated in the high field region flow through the central heavily doped region to the source. For V, , more negative than Vgsmin the point of highest electric field moves to the drain edge of the gated region neare","PeriodicalId":244069,"journal":{"name":"52nd Annual Device Research Conference","volume":"47 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121766741","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Minority carrier transport parameters in n-Si/p+-Si/sub 1-x/Ge/sub x//n-Si HBTs using A.C. and D.C. measurements 利用交流和直流测量n-Si/p+-Si/sub 1-x/Ge/sub x/ n-Si HBTs中的少数载流子输运参数

52nd Annual Device Research Conference Pub Date : 1994-06-20 DOI: 10.1109/DRC.1994.1009406

T. Ghani, J. Hoyt, M. E. Weybright, J. Gibbons

引用次数: 0

Turn-off failure mechanisms in gto thyristors of different anode designs supported by 3-d simulations 三维模拟支持不同阳极设计的gto晶闸管关断失效机制

52nd Annual Device Research Conference Pub Date : 1994-06-20 DOI: 10.1109/DRC.1994.1009404

H. Bleichner, M. Nordgren, M. Rosling, P. Jonsson, E. Nordlander

引用次数: 0

SiGe/Si resonant cavity photodetector SiGe/Si谐振腔光电探测器

52nd Annual Device Research Conference Pub Date : 1994-06-20 DOI: 10.1109/DRC.1994.1009443

S. Murtaza, J. Campbell, J. Bean, L. Peticolas

{"title":"SiGe/Si resonant cavity photodetector","authors":"S. Murtaza, J. Campbell, J. Bean, L. Peticolas","doi":"10.1109/DRC.1994.1009443","DOIUrl":"https://doi.org/10.1109/DRC.1994.1009443","url":null,"abstract":"The smaller absorption coefficient of silicon as compared to direct band-gap III-V compound materials necessitates the use of thick (typically > 5 pm) absorption regions in silicon photodiodes. Although high responsivities can be achieved with the thick absorbing layers, the associated transit times limit bandwidths to 90% [2]. This has made it possible to realize a Sibased resonant-cavity photodiode. The photodiode structure was grown by solid source molecular beam epitaxy. The asymmetric mirror consisted of 40, n-doped (1x1018) G@.gSio.~/Si periods grown on a silicon substrate. The thicknesses of the Geo.30Si0.70 and Si layers were 22581 and 570 81, respectively. The mirror was followed by a 1.03 pm-thick intrinsic silicon absorbing layer. On top of this was grown a 0.2 pm, p-doped (1~10~8) Si layer followed by a 200 81 p+ Si contact layer. The photodetector structure is shown in Fig.1. The simulated and measured reflectivity spectra of the bottom GeSi/Si mirror are shown in Fig. 2. The quantum efficiency of the resonant cavity photodetector was measured by comparing it with a calibrated silicon photodiode. The quantum efficiency curve is shown in Fig. 3. The peak quantum efficiency was found to be 89%. At resonance, essentially all the absorption takes place in the 1.25 pm long cavity. In a conventional photodiode structure, even with a perfect antireflection coating, the absorbing layer would have to be at least 8 times thicker (- 10 pm) to achieve the same responsivity and there would be a comparable decrease in the bandwidth. The calculated, transit-time-limited bandwidth of the resonant-cavity photodiode is greater than 25 GHz, Work is also in progress on novel GexSil-,/Si mirrors and photodetectors that will be resonant at two distinct wavelengths [3]. The dual mirror structure essentially consists of a quarter wavelength asymmetric mirror with additional quarter wavelength layers of Si inserted at appropriate points in the structure to modulate the reflected phase. The measured reflectivity spectrum of a dual wavelength asymmetric mirror is shown in Fig. 4. The two reflectivity peaks are close to 632 nm and 780 nm. A cavity which will be resonant at both the peak wavelengths can be grown on top of this mirror to provide twin-peak resonant cavity photodetectors. Such devices can be used for wavelength-division-multiplexing applications and integrated noise filters.","PeriodicalId":244069,"journal":{"name":"52nd Annual Device Research Conference","volume":"65 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1994-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117021198","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Low threshold vertical-cavity lasers based on native-oxidation of alas 基于alas天然氧化的低阈值垂直腔激光器

52nd Annual Device Research Conference Pub Date : 1994-06-20 DOI: 10.1109/DRC.1994.1009437

D. Huffaker, D. Deppe, K. K. Kumar, T. Rogers

引用次数: 1

High frequency quantum well infrared photodetector 高频量子阱红外光电探测器

52nd Annual Device Research Conference Pub Date : 1994-06-20 DOI: 10.1109/DRC.1994.1009434

H.C. Liu, G.E. Jenskins, E. Brown, K. A. Mcintosh, K. Nichols, M. Manfra

引用次数: 1

Coherent terahertz radiation from LTG-GaAs photomixers LTG-GaAs光合成机的相干太赫兹辐射

52nd Annual Device Research Conference Pub Date : 1994-06-20 DOI: 10.1109/DRC.1994.1009414

K. A. Mcintosh, E. Brown, K.S. Nichols, M. Manfra, C. L. Dennis

引用次数: 0

Transport phenomena in quantum well infrared photodetectors 量子阱红外探测器中的输运现象

52nd Annual Device Research Conference Pub Date : 1994-06-20 DOI: 10.1109/DRC.1994.1009433

C. Lee, K. Choi

引用次数: 0

Bi-color light emitting diode based on the bias dependent collection of electrons and holes in quantum wells 基于偏置相关量子阱中电子和空穴收集的双色发光二极管

52nd Annual Device Research Conference Pub Date : 1994-06-20 DOI: 10.1109/DRC.1994.1009393

R.M. Kolbas, F. Reed, D. Zhang

引用次数: 0

GaInP/GaAs HBTs with selectively regrown emitter and wide bandgap extrinsic base 具有选择性再生发射极和宽禁带外源基的GaInP/GaAs HBTs

52nd Annual Device Research Conference Pub Date : 1994-06-20 DOI: 10.1109/DRC.1994.1009428

S. Fu, S. Park, Y. Hsin, M. Ho, T. Chin, P. Yu, C. Tu, P. Asbeck

引用次数: 7