Fifteen periods of Si/Si0.7Ge0.3 multilayers (MLs) with various SiGe thicknesses are grown on a 200 mm Si substrate using reduced pressure chemical vapor deposition (RPCVD). Several methods were utilized to characterize and analyze the ML structures. The high resolution transmission electron microscopy (HRTEM) results show that the ML structure with 20 nm Si0.7Ge0.3 features the best crystal quality and no defects are observed. Stacked Si0.7Ge0.3 ML structures etched by three different methods were carried out and compared, and the results show that they have different selectivities and morphologies. In this work, the fabrication process influences on Si/SiGe MLs are studied and there are no significant effects on the Si layers, which are the channels in lateral gate all around field effect transistor (L-GAAFET) devices. For vertically-stacked dynamic random access memory (VS-DRAM), it is necessary to consider the dislocation caused by strain accumulation and stress release after the number of stacked layers exceeds the critical thickness. These results pave the way for the manufacture of high-performance multivertical-stacked Si nanowires, nanosheet L-GAAFETs, and DRAM devices.
Since the invention of amorphous indium–gallium–zinc–oxide (IGZO) based thin-film transistors (TFTs) by Hideo Hosono in 2004, investigations on the topic of IGZO TFTs have been rapidly expanded thanks to their high electrical performance, large-area uniformity, and low processing temperature. This article reviews the recent progress and major trends in the field of IGZO-based TFTs. After a brief introduction of the history of IGZO and the main advantages of IGZO-based TFTs, an overview of IGZO materials and IGZO-based TFTs is given. In this part, IGZO material electron travelling orbitals and deposition methods are introduced, and the specific device structures and electrical performance are also presented. Afterwards, the recent advances of IGZO-based TFT applications are summarized, including flat panel display drivers, novel sensors, and emerging neuromorphic systems. In particular, the realization of flexible electronic systems is discussed. The last part of this review consists of the conclusions and gives an outlook over the field with a prediction for the future.
Currently, the global 5G network, cloud computing, and data center industries are experiencing rapid development. The continuous growth of data center traffic has driven the vigorous progress in high-speed optical transceivers for optical interconnection within data centers. The electro-absorption modulated laser (EML), which is widely used in optical fiber communications, data centers, and high-speed data transmission systems, represents a high-performance photoelectric conversion device. Compared to traditional directly modulated lasers (DMLs), EMLs demonstrate lower frequency chirp and higher modulation bandwidth, enabling support for higher data rates and longer transmission distances. This article introduces the composition, working principles, manufacturing processes, and applications of EMLs. It reviews the progress on advanced indium phosphide (InP)-based EML devices from research institutions worldwide, while summarizing and comparing data transmission rates and key technical approaches across various studies.
Artificial intelligence (AI) processes data-centric applications with minimal effort. However, it poses new challenges to system design in terms of computational speed and energy efficiency. The traditional von Neumann architecture cannot meet the requirements of heavily data-centric applications due to the separation of computation and storage. The emergence of computing in-memory (CIM) is significant in circumventing the von Neumann bottleneck. A commercialized memory architecture, static random-access memory (SRAM), is fast and robust, consumes less power, and is compatible with state-of-the-art technology. This study investigates the research progress of SRAM-based CIM technology in three levels: circuit, function, and application. It also outlines the problems, challenges, and prospects of SRAM-based CIM macros.
One of the core semiconductor devices is the electrostatic chuck. It has been widely used in plasma-based and vacuum-based semiconductor processing. The electrostatic chuck plays an important role in adsorbing and cooling/heating wafers, and has technical advantages on non-edge exclusion, high reliability, wafer planarity, particles reduction and so on. This article extracts key design elements from the existing knowledge and techniques of electrostatic chuck by the method proposed by Paul and Beitz, and establishes a design space systematically. The design space is composed of working objects, working principles and working structures. The working objects involve electrostatic chuck components and materials, classifications, and relevant properties; the working principles involve clamping force, residual force, and temperature control; the working structures describe how to compose an electrostatic chuck and to fulfill the overall functions. The systematic design space exhibits the main issues during electrostatic chuck design. The design space will facilitate and inspire designers to improve the design quality and shorten the design time in the conceptual design.
The heterogeneous integration of III–V devices with Si-CMOS on a common Si platform has shown great promise in the new generations of electrical and optical systems for novel applications, such as HEMT or LED with integrated control circuitry. For heterogeneous integration, direct wafer bonding (DWB) techniques can overcome the materials and thermal mismatch issues by directly bonding dissimilar materials systems and device structures together. In addition, DWB can perform at wafer-level, which eases the requirements for integration alignment and increases the scalability for volume production. In this paper, a brief review of the different bonding technologies is discussed. After that, three main DWB techniques of single-, double- and multi-bonding are presented with the demonstrations of various heterogeneous integration applications. Meanwhile, the integration challenges, such as micro-defects, surface roughness and bonding yield are discussed in detail.
Graphene has garnered significant attention in photodetection due to its exceptional optical, electrical, mechanical, and thermal properties. However, the practical application of two-dimensional (2D) graphene in optoelectronic fields is limited by its weak light absorption (only 2.3%) and zero bandgap characteristics. Increasing light absorption is a critical scientific challenge for developing high-performance graphene-based photodetectors. Three-dimensional (3D) graphene comprises vertically grown stacked 2D-graphene layers and features a distinctive porous structure. Unlike 2D-graphene, 3D-graphene offers a larger specific surface area, improved electrochemical activity, and high chemical stability, making it a promising material for optoelectronic detection. Importantly, 3D-graphene has an optical microcavity structure that enhances light absorption through interaction with incoming light. This paper systematically reviews and analyzes the current research status and challenges of 3D-graphene-based photodetectors, aiming to explore feasible development paths for these devices and promote their industrial application.
A single-pole four-throw (SP4T) RF switch with charge-pump-based controller is designed and implemented in a commercial 130-nm silicon-on-insulator (SOI) CMOS process. An improved body self-biasing technique based on diodes is utilized to simplify the controlling circuitry and improve the linearity. A multistack field-effect-transistor (FET) structure with body floating technique is employed to provide good power-handling capability. The proposed design demonstrates a measured input 0.1-dB compression point of 38.5 dBm at 1.9 GHz, an insertion loss of 0.27 dB/0.33 dB and an isolation of 35 dB/27 dB at 900 MHz/1.9 GHz, respectively. The overall chip area is only 0.49 mm2. This RF switch can be used in GSM/WCDMA/LTE front-end modules.


