Browsing by Author "Yang, Chih-Chao"

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A sandwiched buffer layer enabling pulsed ultraviolet- and visible-laser annealings for direct fabricating poly-Si field-effect transistors on the polyimide
(2017-07-10)
Kao, Ming-Hsuan
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Huang, Wen-Hsien
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Shieh, Jia-Min
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Shen, Chang-Hong
;
Lee, Pei-Kang
A sandwiched buffer layer of SiO2/Al/SiO2 enables ultraviolet-laser crystallization and visible-laser activation for direct fabrication of a poly-Si flexible field-effect-transistor (fFET) on polyimides. The buffer layer can produce heat accumulation and laser reflection from the Al/SiO2 interface to facilitate grain growth and contact resistance reduction of poly-Si without damaging the polyimide substrate. The feature size of poly-Si fFET has shrunk to 400nm via laser annealing, with the on/off current-ratio exceeding 5 x 10(6) and a subthreshold swing of 190 mV/dec. Moreover, the transfer characteristics of fFET by tension stress can be maintained until the bending radius reaches over 15 mm. Published by AIP Publishing.
a-SiGeC Thin Film Photovoltaic Enabled Self-Power Monolithic 3D IC Under Indoor Illumination
(2016)
Kao, Ming-Hsuan
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Yang, Chih-Chao
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Wu, Tsung-Ta
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Hsieh, Tung-Ying
;
Huang, Wen-Hsieh
Low temperature a-SiGeC thin film photovoltaic (TFPV) ambient light-energy harvesters monolithically integrated with high performance 3D sequentially stackable device were demonstrated in this article. The 3D stackable device with threshold voltage engineering and driving current boosting technologies enable excellent current controllability to achieve low I-off and high I-on operation condition for integrated circuit design. The monolithically stacking of Si thin-film energy harvester, which provide output power (21.93uW/cm(2)) under 450 lux indoor illumination, envisions self-power and low cost 3D(+)IC for internet of things.
Charge-trap non-volatile memories fabricated by laser-enabled low-thermal budget processes
(2015-11-02)
Huang, Wen-Hsien
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Shieh, Jia-Min
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Pan, Fu-Ming
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Yang, Chih-Chao
;
Shen, Chang-Hong
We fabricated charge-trap non-volatile memories (NVMs) using low thermal budget processes, including laser-crystallization of poly-Si thin film, chemical vapor deposition deposition of a stacked memory layer, and far-infrared-laser dopant activation. The thin poly-Si channel has a low defect-density at the interface with the bulk, resulting in a steep subthreshold swing for the NVM transistors. The introduction of the stacked SiO2/AlOxNy tunnel layer and the SiNx charge-trap layer with a gradient bandgap leads to reliable retention and endurance at low voltage for the NVMs. The low thermal budget processes are desirable for the integration of the nano-scaled NVMs into system on panels. (C) 2015 AIP Publishing LLC.
Double-metal-gate nanocrystalline Si thin film transistors with flexible threshold voltage controllability
(2013-11-11)
Chiou, Uio-Pu
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Shieh, Jia-Min
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Yang, Chih-Chao
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Huang, Wen-Hsien
;
Kao, Yo-Tsung
We fabricated nano-crystalline Si (nc-Si: H) thin-film transistors (TFTs) with a double-metal-gate structure, which showed a high electron-mobility (mu(FE)) and adjustable threshold voltages (V-th). The nc-Si: H channel and source/drain (S/D) of the multilayered TFT were deposited at 375 degrees C by inductively coupled plasma chemical vapor deposition. The low grain-boundary defect density of the channel layer is responsible for the high mu(FE) of 370 cm(2) /V-s, a steep subthreshold slope of 90 mV/decade, and a low V-th of -0.64 V. When biased with the double-gate driving mode, the device shows a tunable V-th value extending from -1V up to 2.7 V. (C) 2013 AIP Publishing LLC.
Enabling n-type polycrystalline Ge junctionless FinFET of low thermal budget by in situ doping of channel and visible pulsed laser annealing
(2017-02)
Huang, Wen-Hsien
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Shieh, Jia-Min
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Kao, Ming-Hsuan
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Shen, Chang-Hong
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Huang, Tzu-En
A low-thermal-budget n-type polycrystalline Ge (poly-Ge) channel that was prepared by plasma in-situ-doped nanocrystalline Ge (nc-Ge) and visible pulsed laser annealing exhibits a high electrically active concentration of 2 x 10(19) cm(-3) and a narrow Raman FWHM of 3.9 cm(-1). Furthermore, the fabricated n-type poly-Ge junctionless FinFET (JL-FinFET) shows an I-on/I-off ratio of 6 x 10(4), V-th of % -0.3 V, and a subthreshold swing of 237mV/dec at V-d of 1V and DIBL of 101mV/V. The poly-Ge JL-FinFET with a high-aspect-ratio fin channel is less sensitive to V-th roll-off and subthreshold-swing degradation as the gate length is scaled down to 50 nm. This low-thermal-budget JL-FinFET can be integrated into three-dimensional sequential-layer integration and flexible electronics. (C) 2017 The Japan Society of Applied Physics
Energy-Efficient Gas Recognition System with Event-Driven Power Control
(2015)
Huang, Chun-Ying
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Huang, Po-Tsang
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Yang, Chih-Chao
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Chuang, Ching-Te
;
Hwang, Wei
For energy-limited applications of electronic nose, an application-specific architecture is essential to realize a low-energy gas recognition system. In this paper, a pseudo-zeroleakage gas recognition system is proposed to recognize different gases using event-driven power control. Additionally, this gas recognition system can recognize four different gases with concentration information by drift-insensitive on-line training, achieving 100% recognition accuracy for gas type and 89.4% accuracy for concentration analysis. For further reducing the overall energy consumption, both near-threshold SRAM and low-voltage embedded ReRAM are integrated into the proposed system, respectively. Based on TSMC 65nm LP CMOS process, the total energy of the gas recognition systems with SRAM and ReRAM are only 8.62 mu J and 2.04 mu J in a sensing period, respectively. Hence, an energy-efficient gas recognition system can be realized by a pseudo-zero-leakage event-driven structure with ReRAM.
First Fully Functionalized Monolithic 3D(+) IoT Chip with 0.5 V Light-electricity Power Management, 6.8 GHz Wireless-communication VCO, and 4-layer Vertical ReRAM
(2016-01-01)
Hsueh, Fu-Kuo
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Shen, Chang-Hong
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Shieh, Jia-Min
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Li, Kai-Shin
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Chen, Hsiu-Chih
For the first time, we report low-cost heterogeneously integrated sub-40nm epi-like Si monolithic internet of thins (IoT) 3D(+)-IC with wireless communication, light-electricity power management and vertical ReRAM (VRRAM) modules. High current driving multi-channel 3D(+) UTB-MOSFETs (600 mu A/282 mu A@V-G = +/- 1V for 10-channel P/N FETs) was fabricated by low thermal budget super-CMP-planarized visible laser-crystallized epi-like Si channel and CO2 far-infrared laser annealing (CO2-FIR-LA) activation technologies that support a 6.8GHz high frequency VCO circuits, 0.5V low-voltage power management circuit and drives 20nm 4-layer VRRAM (Set/Reset <1.2V/1.8V, 3-bits/cell). This unique TSV-free monolithic 3D(+)IC process provides the superiority in 3D hetero-integration; we successfully integrate these circuits in a low cost, small footprint, fully functionalized 3D(+) IoT chip.
Heterogeneously integrated sub-40nm low-power epi-like Ge/Si monolithic 3D-IC with stacked SiGeC ambient light harvester
(2014)
Shen, Chang-Hong
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Shieh, Jia-Min
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Huang, Wen-Hsien
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Wu, Tsung-Ta
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Chen, Chien-Fu
For the first time, we report heterogeneously integrated sub-40nm epi-like Ge/Si monolithic 3D-IC with low-power logic/NVM circuits and efficient photovoltaic energy harvester. Threshold voltage engineering and driving current boosting technologies enable stackable Ge/Si UTB (< 15nm) MOSFETs, CMOS inverter and SRAM (SNM=270mV@0.7V) achieve low operation voltage. Stackable 1-T NVM with high speed (100ns) and low driving-voltage operation provide power-off storage while SRAM serve as power-on working memory. 100% aperture ratio SiGeC ambient light energy harvester with maximum output power of 7mW/cm(2) layered on the monolithic 3D-IC chip envisions a self-powered monolithic 3D-IC technology for advanced low-power wire-less sensor networks, wearable devices, and devices for Internet of Things.
High Performance and Low power Monolithic Three-Dimensional Sub-50 nm Poly Si Thin film transistor (TFTs) Circuits
(2017-05-02)
Wu, Tsung-Ta
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Huang, Wen-Hsien
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Yang, Chih-Chao
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Chen, Hung-Chun
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Hsieh, Tung-Ying
Development of manufacture trend for TFTs technologies has focused on improving electrical properties of films with the cost reduction to achieve commercialization. To achieve this goal, high-performance sub-50 nm TFTs-based MOSFETs with ON-current (I-on)/subthreshold swing (S.S.) of 181 mu A/mu m/107 mV/dec and 188 mu A/mu m/98 mV/dec for NMOSFETs and PMOSFETs in a monolithic 3D circuit were demonstrated by a low power with low thermal budget process. In addition, a stackable static random access memory (SRAM) integrated with TFTs-based MOSFET with static noise margins (SNM) equals to 390 mV at V-DD = 1.0 V was demonstrated. Overall processes include a low thermal budget via ultra-flat and ultra-thin poly-Si channels by solid state laser crystallization process, chemical-mechanical polishing (CMP) planarization, plasma-enhanced atomic layer deposition (ALD) gate stacking layers and infrared laser activation with a low thermal budget. Detailed material and electrical properties were investigated. The advanced 3D architecture with closely spaced inter-layer dielectrics (ILD) enables high-performance stackable MOSFETs and SRAM for power-saving IoT/mobile products at a low cost or flexible substrate.
High Performance Poly Si Junctionless Transistors with Sub-5nm Conformally Doped Layers by Molecular Monolayer Doping and Microwave Incorporating CO2 Laser Annealing for 3D Stacked ICs Applications
(2015)
Lee, Yao-Jen
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Cho, Ta-Chun
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Sung, Po-Jung
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Kao, Kuo-Hsing
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Hsueh, Fu-Kuo
A junctionless (JL) fin thin film transistor (FinTFT) with a novel shell doping profile (SDP) formed by a damage-free conformal molecular monolayer doping (MLD) method and a combination of microwave annealing (MWA) and CO2 laser spike annealing (COLSA) is demonstrated and studied. MWA drives in and partially activates the MLD dopants; the resultant SDP features an ultra-shallow depth (< 5nm) and an abrupt steepness (< 0.8 nm/dec). The dopant activation of the devices experienced MLD and MWA is further enhanced by the nonmelting COLSA without dopant diffusion, and which can also avoid fin deformation and recover surface defects left by fin patterning. Thanks to the enhanced dopant activation by COLSA, the SDP-FinTFTs overall exhibit better performance than the SDP-FinTFTs without COLSA and the conventional implanted (imp) FinTFTs in terms of subthreshold swing (S.S.), on-currents (I-on by 160% compared to the SDP-FinTFTs without COLSA) and on/off current ratio (I-on/I-off > 10(7)) for 3D stacked ICs applications. Our results reveal the potential of the proposed SDP formed by MLD, MWA and COLSA enabling a JLFinTFT showing excellent performance.
Junction-less poly-Ge FinFET and charge-trap NVM fabricated by laser-enabled low thermal budget processes
(2016-06-13)
Huang, Wen-Hsien
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Shieh, Jia-Min
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Shen, Chang-Hong
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Huang, Tzu-En
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Wang, Hsing-Hsiang
A doping-free poly-Ge film as channel material was implemented by CVD-deposited nano-crystalline Ge and visible-light laser crystallization, which behaves as a p-type semiconductor, exhibiting holes concentration of 1.8 x 10(18) cm(-3) and high crystallinity (Raman FWHM similar to 4.54 cm(-1)). The fabricated junctionless 7 nm-poly-Ge FinFET performs at an I-on/I-off ratio over 10(5) and drain-induced barrier lowering of 168mV/ V. Moreover, the fast programming speed of 100 mu s-1 ms and reliable retention can be obtained from the junctionless poly-Ge nonvolatile-memory. Such junctionless poly-Ge devices with low thermal budget are compatible with the conventional CMOS technology and are favorable for 3D sequential-layer integration and flexible electronics. Published by AIP Publishing.
Location-controlled-grain Technique for Monolithic 3D BEOL FinFET Circuits
(2018-01-01)
Yang, Chih-Chao
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Hsieh, Tung-Ying
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Huang, Po-Tsang
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Chen, Kuan-Neng
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Wu, Wan-Chi
A location-controlled-grain technique is presented for fabricating BEOL monolithic 3D FinFET ICs over SiO2. The grain-boundary free Si FinFETs thus fabricated exhibit steep sub-threshold swing (<70mV/doc.), high driving currents (n-type: 363 mu A/mu m and p-type: 385 mu A/mu m), and high I-on/I-off(>10(6)). According to simulation, the thickness of the interlayer dielectric plays an important role and shall be thicker than 250nm so that the sequential pulse laser crystallization process does not heat the bottom devices and interconnects to more than 400 degrees C.
Logic/Memory Hybrid 3D Sequentially Integrated Circuit Using Low Thermal Budget Laser Process
(2015)
Yang, Chih-Chao
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Hsieh, Tung-Ying
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Huang, Wen-Hsien
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Wu, Tsung-Ta
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Wang, Hsing-Hsiang
High performance 3D sequentially stackable nanowire FETs and non-volatile memories (NVMs) with threshold voltage engineering and driving current boosting technologies were demonstrated by using low thermal budget nanosecond laser crystallization and laser activation technologies. The local heating laser process without damaging the underlying device/circuit realizes the across -layer and in -layer integration of high-speed 3ps logic circuits and 1-T 100ns plasma-MONOS NVMs as well as low driving-voltage 6T SRAMs with static noise margin (SNM) of 280 mV. Such logic/memory hybrid 3D sequentially integrated circuit provides power efficient computing and storage. Moreover, the monolithically stacking of Si thin-film energy harvester envisions lower power and low cost 3D(+)IC for internet of things.
Monolithic 3D BEOL FinFET switch arrays using location-controlled-grain technique in voltage regulator with better FOM than 2D regulators
(2019-01-01)
Hsieh, Ping-Yi
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Chang, Yi-Jui
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Chen, Pin-Jun
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Chen, Chun-Liang
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Yang, Chih-Chao
Monolithic 3D back-end of line (BEOL) FinFET switch arrays are demonstrated in large single crystalline Si islands (2.56 mu m(2)), whose location, size and shape are determined by design. Details of the improved location-controlled-grain (LCG) technique are presented. A voltage regulator implemented with the BEOL switch arrays using external control signals shows better theoretical figure of merit (FOM) of 0.089ns than 2D voltage regulators of 0.43ns.
Monolithic 3D Chip Integrated with 500ns NVM, 3ps Logic Circuits and SRAM
(2013)
Shen, Chang-Hong
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Shieh, Jia-Min
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Wu, Tsung-Ta
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Huang, Wen-Hsien
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Yang, Chih-Chao
For the first time, a sequentially processed sub-50nm monolithic 3D IC with integrated logic/NVM circuits and SRAM is demonstrated using multiple layers of ultrathin-body (UTB) MOSFET-based circuits interconnected through 300nm-thick interlayer dielectric (ILD). High-performance sub-50nm UTB MOSFETs using deposited ultra-flat and ultra-thin (20nm) epi-like Si enable across-layer and in-layer high-speed 3ps logic circuits and 1-T 500ns plasma-MONOS NVMs as well as 6T SRAMs with static noise margin (SNM) of 280 mV and reduced footprint by 25%. Closely stacked monolithic 3D circuits envision advanced high-performance, rich function, and low power intelligent mobile devices.
Record-high 121/62 mu A/mu m on-currents 3D stacked epi-like Si FETs with and without metal back gate
(2013)
Yang, Chih-Chao
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Chen, Szu-Hung
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Shieh, Jia-Min
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Huang, Wen-Hsien
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Hsieh, Tung-Ying
A sequential layered integration technology that can fabricate 3D stackable epi-like Si FETs with and without metal back gate (MBG) under sub-400 degrees C are proposed in this article. With laser crystallized epi-like Si and CMP thinning processes for channel fabrication, 3D stackable ultra thin body (UTB) n/p-MOSFETs with low-subthreshold swings (88 and 121 mV/dec.) and high on-currents (121 and 62 liA/Iim) are demonstrated. With additional metal back gate structure, UTB devices can be desirably operated in a positive or negative threshold voltage range with gamma values of 0.51 (n-MOSFETs) and 0.56 (p-MOSFETs) for favoring its applications in 3D logic circuits. In addition, such thin and high quality channel and metal back gate scheme is not only promising for conventional p-n junction device but also junctionless (JL) scheme, which can simplify the fabrication and achieve further scaling.
Transient Thermal Damage Simulation for Novel Location-Controlled Grain Technique in Monolithic 3D IC
(2019-01-01)
Chen, Pin-Jun
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Shen, Chih-Ming
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Yang, Chih-Chao
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Tai, Ming-Chi
;
Lo, Wei-Chung
In this research, Finite Element Method (FEM) is used to simulate transient thermal conduction in the monolithic three-dimensional integrated circuit (3DIC) with a novel location-controlled-grain (LCG) technique. Through this method, the impact of laser flux, amorphous Si thickness and interlayer dielectric (ILD) thickness on that model can be investigated. Furthermore, with the assistance of thermal damage simulation, we can utilize the optimal process parameters in this state-of-the-art technique to accelerate the development of advanced semiconductor technologies.