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ispartof: IEEE TRANSACTIONS ON ELECTRON DEVICES vol:69 issue:9 pages:5357-5362 status: published

In order to meet the requirement of ultrahigh-speed, low latency, and wide bandwidth (BW) in the next 5G mobile network and internet of things (IoT) applications, the parasitic capacitance specification of electrostatic discharge (ESD) protection devices should become much stricter. Reducing the capacitance always degrades the ESD performance in terms of shrinking the size of the ESD protection device. The distributed ESD protection network is one of the solutions which mitigates the capacitance issue and provides a broadband design. However, while the ESD devices are put under the I/O pad in the distributed ESD protection network, back-end-of-line (BEOL) capacitance starts to play an important role in the advanced 28-nm CMOS process. Therefore, a tapered metal structure is proposed to significantly reduce 30% BEOL capacitance of the ESD device, which can gain a 2.8-GHz increase in the operational BW in the distributed network. Meanwhile, it can enhance the human-body-model (HBM) level up to 16% higher than the original layout style under the same front-end-of-line (FEOL) layout size.

The sensitivity of latch-up to wafer thickness is investigated with TCAD simulations. The dependency of bipolar and well resistances on substrate thickness is first evaluated, and later used to assess the loop gain of the latch-up circuit. Transient simulations are finally employed to assess the latch-up resilience as a function of substrate thickness.

In this paper, Gallium Nitride (GaN) Metal-Insulator-Semiconductor (MIS)-HEMTs are compared with conventional Schottky Metal-Semiconductor HEMTs in terms of DC and ESD performance. Measurement results indicate TLP failures are highly related to 2DEG channel driving capability. The impacts of different gate interfaces in the GaN (MIS)-HEMTs on failure mechanisms are the key factor of final ESD robustness.

ESD robustness for self-protected advanced Silicon photonic components integrated into optical interposers is reported, including industry-first CDM data. HBM performance in reverse bias polarity is shown to be the limiting factor and is correlated to the optical component width. The Ge-EAM modulator with heater is found to be the weakest element CDM-wise.

With the integrated circuit technology evolution towards 25D and 3D stacking, wafer-level and bare-die-level electrostatic discharge testing is becoming a necessity. In this work, we use our Low-Impedance Contact CDM tester to measure integrated circuit products and assess the possibilities and potential issues of CDM testing of wafers and bare dies.

Three-dimensional particle-in-cell simulations are conducted to investigate the self-compression of a sub-terawatt (TW) laser pulse when propagating in a thin, dense gas target. In this way, the interplay of ionization of gas atoms, defocusing and diffraction of laser fields cause the phase modulation and spectral broadening required to realize a short duration for the output pulse 1 , 2 .

Wakefield acceleration has been considered as a candidate of the origin of cosmic rays and the electron power-law spectra with an index of −2 and it has been demonstrated experimentally and numerically. In order to further support the universality of wakefield acceleration to address the power-law spectra of cosmic rays, we investigate the nonthermal acceleration of relativistic electrons due to the laser-induced wakefield acceleration with a static external magnetic field using two-dimensional particle-in-cell simulation.The results indicate that the power-law spectra with an index of −2 still remain even in the presence of external magnetic field.

For sub-5 nm bulk Si CMOS, a gate-all-around (GAA) nanowire (NW) device is a promising candidate. The new device architecture will have an impact on the transient performance of an electrostatic discharge protection diode. The 100 ns transmission line pulse (TLP) and 2 ns very fast TLP measurement results and TCAD simulations prove that the performance in bulk GAA NW-based diodes is maintained in comparison to bulk FinFET diodes.

Atomically thin graphene is a transparent, highly electrically and thermally conductive, light-weight, and the strongest material. To date, graphene has found applications in many aspects including transport, medicine, electronics, energy, defense, and desalination. We demonstrate another disruptive application of graphene in the field of laser-ion acceleration, in which the unique features of graphene play indispensable role. Laser driven ion sources have been widely investigated for pure science, plasma diagnostics, medical and engineering applications. Recent developments of laser technologies allow us to access radiation regime of laser ion acceleration with relatively thin targets. However, the thinner target is the less durable and can be easily broken by the pedestal or prepulse through impact and heating prior to the main laser arrival. One of the solutions to avoid this is plasma mirror, which is a surface plasma created by the foot of the laser pulse on an optically transparent material working as an effective mirror only for the main laser peak. So far diamond like carbon (DLC) is used to explore the ion acceleration in extremely thin target regime (< 10 nm) with plasma mirrors, and it is necessary to use plasma mirrors even in moderately thin target regime (10-100 nm) to realize energetic ion generation. However, firstly DLC is not 2D material, and therefore, it is very expensive to make it thin and flat. Moreover, graphene is stronger than diamond at extremely thin regime, and much more reasonable for mass-production. Furthermore, installing and operating plasma mirrors at high repetition rate is also costly. Here we show another direct solution using graphene as the thinnest and strongest target ever made. We develop a facile transfer method to fabricate large-area suspended graphene (LSG) as target for laser ion acceleration with precision down to a single atomic layer. Direct irradiation of the LSG targets with an ultra intense laser generates energetic carbons and protons evidently showing the durability of graphene without plasma mirror. This extends the new frontier of science on graphene under extreme electromagnetic field, such as energy frontier and nuclear fusion.

This article presents practical design considerations and methodologies for a 28-GHz front-end module (FEM) in 22-nm fully depleted silicon on insulator (FD-SOI) CMOS technology for the fifth generation (5G) wireless communication. The design adopts a gain-boosting technique that is comprehensively analyzed with a transformer-based stacked-FET power amplifier (PA). Then, the co-design of the transmit/receive (T/R) switch with the PA and low-noise amplifier (LNA) is investigated, and an electrostatic-discharge (ESD)-aware T/R switch incorporating PA circuitry is proposed to leverage the Tx- and Rx-mode performance. Moreover, the robustness of standalone PA and Tx-mode FEM is simulated and experimentally verified. Furthermore, the ground return paths and supply parasitic paths of the adopted single-ended LNA together with the proposed T/R switch are studied, properly simulated, and assessed. Finally, the proposed PA topology is first verified standalone, exhibiting 32-dB power gain (Gp), an 18.2-dBm output 1-dBcompression point (OP1 dB), and a 31.1% power-added efficiency (PAE) at OP1 dB (PAE1 dB). Using this PA in the FEM yields a Tx-mode OP1 dB/PAE1 dB of 16 dBm/19.4%, and an average output power (Poutavg)/PAE of 10.1 dBm/8.3% for a 100-MHz bandwidth 256-QAM single-carrier signal at an error-vector magnitude (EVM) of -30 dB. In the Rx mode, noise figure (NF) and input-referred third-order intercept point (IIP3) are 3.2 and -5.4 dBm, respectively. A 2-kV human-body model (HBM) ESD protection of the FEM is predicted in transient simulations and measured with transmission line pulse (TLP) tests.

We propose a table-top linearly polarized hard X-ray source by using a tilted shock-front injection in a laser wakefield accelerator (LWFA) to achieve comprehensive control of both polarization and energy of X-ray. By using shock-front injection, the electron bunches are injected during a sharp transition of plasma density. The length of density transition is significantly shorter than the plasma wavelength and offers a highly localized injection. In regular injection methods, such as self and ionization injection, the majority of electrons are injected radially symmetrically. Particle-in-cell (PIC) simulations show the tilted shock front breaks radial symmetry of injection and creates coherent in-plane oscillation of electrons. The coherence of electron bunches is maximized around 30 degrees which leads to a linearly polarized betatron radiation. The polarization of the resulting X-ray is analyzed by Bragg diffraction after collimation by a polycapillary lens.