Lateral Bipolar Transistor Research Articles

Room temperature VOC gas detection using a gated lateral BJT with an assembled solvatochromic dye

A novel volatile organic compound (VOC) gas sensor utilizing a gated lateral bipolar junction transistor (BJT) with an assembled solvatochromic dye is proposed. Because of its threshold voltage, the proposed gas sensor device can be used under room temperature conditions, unlike common semiconductor-based gas sensors. For this study, a metal-oxide-semiconductor field-effect transistor (MOSFET)-gated lateral, hybrid mode-operated BJT that could be driven using base current control with a gate bias supply was zero. A solvatochromic 4-amino-N-methylphthalimide (4-ANMP) dye, which had its molecules immobilized on the floating gate of the gated lateral BJT using a self-assembled monolayer (SAM) method based on the amino-group holding within its molecular structure, was also used. The charge-transfer (CT) property of this dye could respond to changes in polarities of gases and solutions in the surrounding environment. In this study, three types of VOC gases, namely, benzene, hexane, and acetic acid gas, were detected. It was shown that, by using the proposed sensor, the acetic acid gas and the benzene gas could be detected at room temperature at sensitivities of approximately 0.046 and 0.052μA/decade for benzene and acetic acid gas, respectively. And the non-polar hexane gas could not be detected.

The Dependence of Retention Time on Gate Length in UTBOX FBRAM With Different Source/Drain Junction Engineering

The floating-body-RAM sense margin and retention-time dependence on the gate length is investigated in UTBOX devices using BJT programming combined with a positive back bias (so-called V th feedback). It is shown that the sense margin and the retention time can be kept constant versus the gate length by using a positive back bias. Nevertheless, below a critical L, there is no room for optimization, and the memory performances suddenly drop. The mechanism behind this degradation is attributed to GIDL current amplification by the lateral bipolar transistor with a narrow base. The gate length can be further scaled using underlap junctions.

Bipolar Charge-Plasma Transistor: A Novel Three Terminal Device

A distinctive approach for forming a lateral bipolar charge-plasma transistor (BCPT) is explored using 2-D simulations. Different metal work-function electrodes are used to induce n- and p-type charge-plasma layers on undoped silicon-on-insulator (SOI) to form the emitter, base, and collector regions of a lateral n-p-n transistor. Electrical characteristics of the proposed device are simulated and compared with that of a conventionally doped lateral bipolar junction transistor (BJT) with identical dimensions. Our simulation results demonstrate that the BCPT concept will help us realize a superior bipolar transistor in terms of a high current gain, as compared with a conventional BJT. This BCPT concept is suitable in overcoming doping issues such as dopant activation and high-thermal budgets, which are serious issues in ultrathin SOI structures.

Extraction Enhanced Lateral Insulated Gate Bipolar Transistor: A Super High Speed Lateral Insulated Gate Bipolar Transistor Superior to Lateral Dobule Difused Metal Oxide Semiconductor Field-Effect Transistor

Extraction Enhanced Lateral Insulated Gate Bipolar Transistor: A Super High Speed Lateral Insulated Gate Bipolar Transistor Superior to Lateral Dobule Difused Metal Oxide Semiconductor Field-Effect Transistor

The Investigation of Electrothermal Characteristics of High-Voltage Lateral IGBT for ESD Protection

In this paper, the detailed characterizations of the lateral insulated-gate bipolar transistor (LIGBT) for the electro- static discharge (ESD) protection of power ICs are presented. Compared with the conventional lateral DMOS with the same structure except for the anode doping type, the LIGBT shows lower triggering voltage, faster voltage-clamping speed, and much higher ESD robustness. Experimental results demonstrate that the LIGBT with runway layout achieves excellent thermal breakdown current of more than 10 A with 250-μm device width. The high ESD performance enables the LIGBT to be used as a promising ESD protection device in the power ICs.

Quantitative separation of radiation induced charges for gate controlled later PNP bipolar transistors

A new test structure of gate controlled lateral PNP bipolar transistors designed and fabricated. An independent gate terminal is patterned on the oxide layer above the active base region of normal lateral PNP bipolar transistors. According to the gate sweep technique, by sweeping the voltage applied to the gate terminal, one can obtain the characteristic of base current versus gate voltage. The quantitative variations of oxide trapped charges and interface traps are analytically estimated and numerically calculated, and the radiation induced defects in the gate controlled lateral PNP bipolar transistors during 60Co-γ irradiation and annealing at room temperature are separated independently. The test structures and measurements of the bipolar transistors used in the experiment are introduced in detail in this paper.

Use the subthreshold-current technique to separate radiation induced defects in gate controlled lateral pnp bipolar transistors

In this paper, we design and fabricate a new test structure of bipolar device. A gate is deposited on the oxide layer covering the base region of normal lateral pnp bipolar transistor. The characteristic of drain current (collector current) versus the gate voltage is recorded by sweeping the voltage applied to the gate, then the subthreshold-current technique is used to separate the radiation induced oxide trapped charges and interface traps in the gate controlled lateral pnp bipolar transistor during 60Co- irradiation. The test structure and the measurement of the bipolar transistor used in the experiment are introduced in detail in this paper.

Low substrate-current and high breakdown voltage JI-LIGBT

A novel bulk junction isolated lateral insulated gate bipolar transistor (JI-LIGBT) with a heavily doped buried-layer in substrate is presented. Due to electric field modulation and current-gain reduction of the vertical parasitic transistor from the buried-layer, in comparison with the conventional LIGBT without a buried-layer, the novel structure offers not only high breakdown voltage but also short turn-off time and significantly low substrate leakage current.

Volatile Organic Compound Gas Sensor Using a Gated Lateral Bipolar Junction Transistor

In this paper, we report the fabrication of a gated lateral bipolar junction transistor (LBJT) that is used as a sensor for volatile organic compound (VOC) gases. The proposed sensor was fabricated using a standard 0.35-μm process. The sensor can function as both a metal-oxide-semiconductor field-effect transistor (MOSFET) and a BJT. The floating gate of the sensor was coated with a solvatochromic dye, which exhibits charge-transfer (CT) characteristics, as the sensing membrane of the sensor. The gated LBJT was driven under emitter (source) bias and base current control. Owing to the interaction of the VOC gas with the sensing membrane, the emitter (source) current value changed; this change was detected by using a semiconductor test and analyzer (STA-EL421, ELECS). Results show that our fabricated semiconductor-based gas sensor can be effectively used under normal temperature.

VOC Gas Sensing Based on the BJT Mode of Gated LBJT Device

Volatile organic compounds (VOCs) gas sensor based on gated lateral bipolar junction transistor (LBJT) was developed in this study. The device was fabricated using 0.35-μm logic process by Magnachip-Hynix Co. Ltd. under the Integrated Circuit Design education Center Multi Project Wafer (IDEC-MPW) program. Solvatochromic dye as the sensing membrane was coated on the floating gate of the device. A semiconductor test and analyzer (STA-EL421, ELECS) was used to measure the sensing results. Following the results, we found that the sensing device which used the gated LBJT device has fast responsibility and reversibility to VOC gases (acetone etc.).

MOSFET–BJT hybrid mode of the gated lateral bipolar junction transistor for C-reactive protein detection

In this study, we propose a novel biosensor based on a gated lateral bipolar junction transistor (BJT) for biomaterial detection. The gated lateral BJT can function as both a BJT and a metal-oxide-semiconductor field-effect transistor (MOSFET) with both the emitter and source, and the collector and drain, coupled. C-reactive protein (CRP), which is an important disease marker in clinical examinations, can be detected using the proposed device. In the MOSFET–BJT hybrid mode, the sensitivity, selectivity, and reproducibility of the gated lateral BJT for biosensors were evaluated in this study. According to the results, in the MOSFET–BJT hybrid mode, the gated lateral BJT shows good selectivity and reproducibility. Changes in the emitter (source) current of the device for CRP antigen detection were approximately 0.65, 0.72, and 0.80μA/decade at base currents of −50, −30, and −10μA, respectively. The proposed device has significant application in the detection of certain biomaterials that require a dilution process using a common biosensor, such as a MOSFET-based biosensor.

Variable-Gain, Low-Noise Amplification for Sampling Front Ends

This paper presents a low-noise front-end amplifier with configurable gain, targeting the recording of small signals, such as the electrocardiogram (ECG) or electroneurogram (ENG). The circuit consists of a continuous-time input stage using lateral bipolar transistors realized in complementary metal-oxide semiconductor (CMOS) technology followed by a switched-capacitor integrating stage. The voltage gain is adjustable by varying the phase delay between two system clocks. Simulated and measured results for a chip fabricated in 0.35-μm CMOS technology are reported. The amplifier occupies an active area of 0.064 mm(2), yields a nominal gain of 630 V/V with more than a 50-dB tuning range, less than 16 nVrms/√Hz input noise and a common-mode rejection of more than 97 dB. Its power consumption is 280 μW with a ±1.5-V supply.

A low-noise front-end for multiplexed ENG recording using CMOS technology

Multi-electrode cuffs (MECs) have been proposed as a means for the parallel recording of naturally-occurring neural signals. Compared to a conventional tripole cuff providing a single channel signal, additional information about the velocity and direction of nerve signals can be extracted from the multi-electrode recordings. Moreover, interference suppression is improved as the presented analysis shows. In this paper a new recording system is proposed, each channel of which consists of a low-noise input buffer employing lateral bipolar transistors to provide an impedance match to the tissue and a path to ground for the switching currents of a single high-gain amplifier, which is multiplexed between channels. The proposed system provides low-noise, low-power operation and practically identical channel gains and is suitable for integration in a CMOS process.

Fin-Width Dependence of BJT-Based 1T-DRAM Implemented on FinFET

This letter investigates fin-width dependence on single-transistor latch (STL) for bipolar-junction-transistor (BJT)-based 1T-DRAM through experiments. The minimum drain voltage <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$(V_{\rm latch})$</tex></formula> for the activation of a parasitic lateral BJT in SOI FinFET was measured at various gate lengths ( <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$L_{G}$</tex></formula> 's) and fin widths ( <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex Notation="TeX">$W_{\rm fin}$</tex></formula> 's). The multiplication factor and current gain of the parasitic BJT in SOI MOSFET are introduced as determinant factors. The experimental results clearly show that the value of <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$V_{\rm latch}$</tex></formula> is reduced in a shorter <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$L_{G}$</tex></formula> and wider <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$W_{\rm fin}$</tex></formula> device. It was found that the nonlocal effect retards the reduction of <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$V_{\rm latch}$</tex></formula> as FinFET scales down.

The Effects of Aging and Hydrogen on the Radiation Response of Gated Lateral PNP Bipolar Transistors

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> Complex interplay between hydrogen-related defect formation and passivation is observed in irradiated bipolar transistors. Hydrogen soaking experiments are performed to evaluate the dependence of defect buildup and annealing in gated lateral bipolar transistors on hydrogen exposure. Comparisons of the radiation responses of transistors tested in 2009 to identical devices from the same wafer tested in 2003 show that aging has reduced the amount of radiation-induced interface trap and oxide trapped charge formation in most cases. These results demonstrate that the way in which the radiation response of a hydrogen-sensitive device evolves with age depends on whether hydrogen is diffusing into or out of the device, and whether the initial defect concentration favors passivation or depassivation reactions. These results strongly suggest that hydrogen exposure cannot replace low-dose-rate irradiation in ELDRS tests for bipolar devices and ICs without extensive characterization testing. </para>

A 0.52 ppm/°C high-order temperature-compensated voltage reference

This paper proposed a new high-order curvature compensation technique for a new bandgap voltage reference structure using the temperature characteristics of current gain β and emitter bandgap narrowing factor ΔE G of a lateral NPN bipolar transistor. The new structure can produce two voltage references, which are 1.209 and 2.418 V, respectively. The simulation results show that the temperature coefficients of the two output voltage are 0.52 ppm/°C, the PSRR is more than 60 dB for frequencies at 10 kHz, and the circuit dissipates 0.18 mW with 5-V supply.

A novel high breakdown voltage lateral bipolar transistor on SOI with multizone doping and multistep oxide

A novel high breakdown voltage lateral bipolar junction transistor (LBJT) on silicon-on- insulator (SOI) is proposed. The novelty of the device is the use of the combination of multistep-doped drift region and multistep buried oxide. The steps in doping and in oxide thickness have been used as a replacement for much complex linearly varying drift doping and linearly varying oxide thickness. The LBJT structure incorporating the combination of multistep doping and multistep oxide is analyzed for electrical characteristics using a two-dimensional numerical simulator MEDICI. Numerical simulation has demonstrated that the breakdown voltage of the proposed device with a two-zone step doped (TZSD) drift region is >150% higher than the conventional device. It has been observed that increasing the number of doping zones to 3 from 2 results in a >40% rise in breakdown voltage. The proposed device gives high breakdown voltage even at high doping concentration in the collector drift region. This reduces the on-resistance of the device and thus improves its speed. The dependence of breakdown voltage on various device parameters has been extensively studied to achieve optimum device performance. A process flow for the device fabrication is also being proposed.

Method to extract MOSFET substrate resistance using DC data of base resistance in parasitic BJT

A new DC method is proposed to extract the substrate resistance in MOSFETs by using current-dependent base resistance of parasitic lateral bipolar junction transistor without a complex RF extraction method. The extracted substrate resistance values using the new method match well with those using the RF one, verifying the accuracy of the new method.

A novel nanoscale high breakdown voltage lateral bipolar junction transistor on silicon-on-insulator

A novel nanoscale lateral bipolar junction transistor (LBJT) on silicon-on-insulator (SOI) with buried oxide double step (BODS) structure is proposed. Numerical simulations demonstrate that the breakdown voltage of the proposed device is significantly higher than that of the conventional device. An increase of 150% in breakdown voltage has been obtained in the proposed device. The increase in the breakdown voltage is due to the creation of an additional electric field peak in the collector drift region, leading to greater uniformity in the horizontal component of the surface electric field and hence increases in the breakdown voltage.

Effects of Hydrogen on the Radiation Response of Bipolar Transistors: Experiment and Modeling

Reactions of H2 in lateral PNP BJTs are investigated through experiments and simulations. Pre-irradiation hydrogen exposure makes the devices more sensitive to ionizing radiation, which is explained through first-principles calculations and numerical simulations. Mechanisms for the cracking of hydrogen molecules and proton generation are proposed. We also suggest a mechanism of formation of border traps. When protons are trapped by oxygen vacancies right at or very near the interface, they form electrically active defects near the middle of the band gap. Activation energies of the reaction are used to construct rate equations. The rate equations are solved numerically to determine the spatial and temporal concentrations of hydrogen, holes, and protons. The calculated concentrations of interface and border traps agree well with the experimental results and help to explain the role of hydrogen in determining the total-dose response of BJTs.