Chia-Yi Lin

A CMOS-Compatible Poly-Si Nanowire Device with Hybrid Sensor/Memory Characteristics for System-on-Chip Applications

This paper reports a versatile nano-sensor technology using “top-down” poly-silicon nanowire field-effect transistors (FETs) in the conventional Complementary Metal-Oxide Semiconductor (CMOS)-compatible semiconductor process. The nanowire manufacturing technique reduced nanowire width scaling to 50 nm without use of extra lithography equipment, and exhibited superior device uniformity. These n type polysilicon nanowire FETs have positive pH sensitivity (100 mV/pH) and sensitive deoxyribonucleic acid (DNA) detection ability (100 pM) at normal system operation voltages. Specially designed oxide-nitride-oxide buried oxide nanowire realizes an electrically Vth-adjustable sensor to compensate device variation. These nanowire FETs also enable non-volatile memory application for a large and steady Vth adjustment window (>2 V Programming/Erasing window). The CMOS-compatible manufacturing technique of polysilicon nanowire FETs offers a possible solution for commercial System-on-Chip biosensor application, which enables portable physiology monitoring and in situ recording.

A fully integrated hepatitis B virus DNA detection SoC based on monolithic polysilicon nanowire CMOS process

Polysilicon nanowire (poly-Si NW) based biosensor is integrated with the wireless acquisition circuits in a standard CMOS SoC for the first time. To improve detection quality, a chopper DDA-based analog front-end with features of low noise, high CMRR, and rail-to-rail input range is implemented. Additional temperature sensor is also included to compensate temperature drift of the biosensor. The results indicate that the detection limit is as low as 10fM. The capability to distinguish one base-pair mismatched DNAs is also demonstrated.

Magnetic-composite-modified polycrystalline silicon nanowire field-effect transistor for vascular endothelial growth factor detection and cancer diagnosis.

This study proposes a vascular endothelial growth factor (VEGF) biosensor for diagnosing various stages of cervical carcinoma. In addition, VEGF concentrations at various stages of cancer therapy are determined and compared to data obtained by computed tomography (CT) and cancer antigen 125 (CA-125). The increase in VEGF concentrations during operations offers useful insight into dosage timing during cancer therapy. This biosensor uses Avastin as the biorecognition element for the potential cancer biomarker VEGF and is based on a n-type polycrystalline silicon nanowire field-effect transistor (poly-SiNW-FET). Magnetic nanoparticles with poly[aniline-co-N-(1-one-butyric acid) aniline]-Fe3O4 (SPAnH-Fe3O4) shell-core structures are used as carriers for Avastin loading and provide rapid purification due to their magnetic properties, which prevent the loss of bioactivity; furthermore, the high surface area of these structures increases the quantity of Avastin immobilized. Average concentrations in human blood for species that interfere with detection specificity are also evaluated. The detection range of the biosensor for serum samples covers the results expected from both healthy individuals and cancer patients.

Nickel Silicide Formation using Pulsed Laser Annealing for nMOSFET Performance Improvement

The formation of a uniform, high tensile stress and low silicide/Si interfacial resistance nickel silicide in nMOSFET by introducing pulsed laser annealing (PLA) is reported. This annealing approach facilitated the phase transformation of nickel silicide to Si-rich NiSix compounds using a low-thermal-budget process, improves the silicide/Si interface regularity and avoids familiar (111) NiSi2 facet formation at a laser energy of 1.5 J cm � 2 . By increasing laser energy density up to 2.3 J cm � 2 , the device performance and statistics junction leakage distribution were degraded due to the increased sheet resistance of silicide layer and the destroyed silicide/Si interface morphology. When the PLA with a laser energy density of 1.5 J cm � 2 was employed for nickel silicidation on the p-type Schottky diodes, a 0.16 eV hole Schottky barrier height (SBH) increase from 0.52 to 0.68 eV was observed. In addition, the

A novel smart nanowire biosensor with hybrid sensor/memory/CMOS technology

For the first time, a novel smart biosensor with hybrid sensor/memory/CMOS poly-Si nanowire technology has been developed. Special designed oxide-nitride-oxide composite dielectric underneath 50nm nanowire realizes an electrically Vth-adjustable sensor to compensate device variation. The detections of pH, hydrogen peroxide and DNA are demonstrated using various functionalized receptors. A substrate-ionic coupling operation of the buried-channel field-effect sensor exhibits superior pH sensitivity (Vth shift > 100mV/pH) beyond Nernst limitation. The built-in memory of nanowire devices possess steady electrically Vth adjustment (Vth programming/erasing window > 2V), enable portable physiology monitoring and in-situ recording. In this work, we report a fully CMOS-compatible technique for Lab-on-Chip biosensor application.

Fabrication of High-Sensitivity Polycrystalline Silicon Nanowire Field-Effect Transistor pH Sensor Using Conventional Complementary Metal–Oxide–Semiconductor Technology

High-sensitivity polycrystalline silicon (poly-Si) nanowire field-effect transistor (NW FET) pH sensors using top-down and self-aligned fabrication approaches involving the conventional complementary metal–oxide–semiconductor (CMOS) process are reported. For the top-down NW FET, the shrinkage due to reoxidation enables the nanowire width to be scaled to 40 nm without requiring the use of extra lithography equipment, and this improves the electrical uniformity and the performance of the sensors. The surface-ionic coupling operation of this buried-channel field-effect sensor exhibits superior pH sensitivity (threshold voltage shift > 100 mV/pH) as compared to the surface-channel ion-sensitive FET (ISFET). In addition, we report a novel method for fabricating self-aligned, vertical-channel, poly-Si nanowire sensors. The resulting 65-nm self-aligned vertical-channel poly-Si device was found to be feasible for independent-gate bias control, thus enabling its possible integration in very-large-scale integration (VLSI) circuits. Both the abovementioned approaches enable the manufacture of nanowire devices on a large-scale integrated (LSI) circuit using only CMOS manufacturing processes; this provides a high sensitivity, compact and cost-efficient biosensor systems-on-a-chip application.

Performance Enhancement of the nMOSFET Low-Noise Amplifier by Package Strain

The package strain improves the noise figure (NF) of the low-noise amplifier (LNA). The maximum noise reduction is ~0.53 dB (13%) at the operating frequency of 2.4 GHz under the biaxial tensile strain of 0.037%. The NF reduction of the strained LNA is mainly due to the enhanced transconductance and cutoff frequency of the individual nMOSFET device under the same strain and bias conditions

Sub-fM DNA sensitivity by self-aligned maskless thin-film transistor-based SoC bioelectronics

This is the first study to successfully achieve record DNA sensitivity (sub-fM) by self-aligned, maskless, dual-channel, and metal-gate-based thin-film transistor nano-wire FET. Both novel device architecture (dual-channel) and optimization of integration processes (microcrystalline silicon and self-aligned sidewall sub-50 nm critical dimension) of nano-wire FET enhance the sensitivity to biological entities substantially. Meanwhile, the proposed device is accomplished with an embedded VLSI CMOS circuit. It can thus offer high application potential to pH, protein, and DNA probing in SoC-based portable bioelectronics.

Random Telegraph Noise in 1X-nm CMOS Silicide Contacts and a Method to Extract Trap Density

The behavior of random telegraph noise was affected by nickel silicide barrier height engineering in advanced nano-CMOS technologies. Contact resistance fluctuations with magnitude of up to 40% were observed when a Schottky barrier was reduced to 0.2 eV. The large contact resistance instability is attributed to the barrier modification by positive charge trapping and detrapping in a Schottky contact. The prevalence and magnitude of the noise are dependent on the contact area, trap density, trap energy, and the silicide Schottky barrier height. In this letter, we propose a fast method to extract the density of responsible contact traps.

A 3-D Stackable Maskless Embedded Metal-Gate Thin-Film-Transistor Nanowire for Use in Bioelectronic Probing

Using a self-aligned sidewall microcrystalline-silicon (μc-Si) dual channel, comprising a sub-50-nm channel width, a novel 3-D stackable maskless embedded metal-gate thin-film-transistor nanowire device was fabricated on top metal using a tungsten gate-stack and trilayered oxide/nitride/oxide gate dielectric. The results of using a charge-transferring mechanism based on the solution-phased pH of a phosphate buffer solution and vascular endothelial growth factor showed that μc-Si surfaces exhibit high potential for use in bioelectronics. The device exhibits long-term reliability regarding bioelectronic probing and is as reliable as the commercially available enzyme-linked immunosorbent assay when conducting a targeted, 100-day therapy for ovarian cancer. Thus, the proposed device exhibits potential for use in label-free, economical, and highly reliable lab-on-chip 3-D applications.