About Instruments Today No. 233


Dr. Meng-Fan Luo, Director General of Department of Natural Sciences and Sustainable Development, National Science and Technology Council -The Important Thing in Science Is Not So Much to Obtain New Facts As to Discover New Ways of Thinking About Them

Claire Lin

Advanced Two-dimensional Semiconductors: Material Synthesis and Device Applications

Special Issue Introduction of “Advanced Two-dimensional Semiconductors: Material Synthesis and Device Applications”

Wen-Hao Chang

Key Technologies and Applications of Low-dimensional Semiconductor Materials

Yuan-Ting Chang, Ching-Yuan Su

Based on the excellent electrical transport properties, low-dimensional nanomaterials, including one-dimensional carbon nanotubes (CNTs) and two-dimensional layered materials (2D materials), are evaluated as candidates for future advanced IC processes. However, many bottlenecks still exist in getting into the integration of semiconductor devices. This includes waferscaled synthesis with lower defects and controllable assembly technology. Moreover, there is still a big gap in how to be compatible with the current silicon-based semiconductor process. This article will introduce the key technologies for synthesizing and assembling low-dimensional materials and the unique advantages for future device applications.

2D Device Fabrication and Technique on Monolithic 3D Integration of 2D Transition Metal Dichalcogenides

Yann-Wen Lan, Wen-Hao Chang, Tilo H. Yang

Different from the traditional silicon-based semiconductor industry applications, the development of 2D semiconductor materials with an atomic layer thickness has also been paid more and more attention. However, since the development of this technology is deeply affected by the interface between the material and the metal electrode, it is desirable to solve the contact resistance issue, so as to the industry with the possible application of ultra-high-efficiency electronic components. This article introduces the strategy for 2D electronics with low contact resistance developed by our laboratory and the technique on monolithic 3D integration of the 2D semiconductor transistor. The proposed fabrication process can provide a feasible way to achieve the 3D integration with the existing semiconductor manufacturing process. This process is promising to achieve a large-scale fabrication of 2D material transistors and boost up the further development of monolithic 3D integrated circuits.

The Application of MoS2 Nanodisks in Floating Gate Memory

Han-Hsiang Tai, Yang Yuan Su, Jer-Chyi Wang, Chao-Sung Lai

In recent years, the nonvolatile memories (NVMs) are continuously scaled because of the evolution of semiconductor process technology, which faces various challenges of device performances. Thus, the researchers have attempted to propose lots of methods and structures to solve the problems of characteristics degradation. The two-dimensional material (2D material) with atomic-level thickness and excellent properties has considered as one of the promising candidates for next-generation devices. In this study, the monolayer molybdenum disulfide (MoS2) was fabricated as nanodisks (NDs) and applied as the charge storage sites of NVMs. The MoS2 film was deposited on silicon dioxide (SiO2) films by the low-pressure chemical-vapor-deposition system (LPCVD) and then patterned by the hard mask of gold nanoparticles via the rapid thermal annealing (RTA) and etching processes to form the MoS2 NDs. The memory devices with MoS2 NDs exhibited a memory window of 2.45 V, the charge loss of approximately 14 % after 10 years and the endurance of more than 8 × 104 cycles. The self-aligned technology and the memory devices with MoS2 NDs proposed in this work have considerable potential for the development of
next-generation NVMs.

Numerical Simulation of Flow Field in Multidirectional Inlet Chemical Vapor Deposition System

Hua-Lin Chen, Wei-Chun Chen, Hung-Pin Chen, Che-Chin Chen, Yu-Wei Lin, Fong-Zhi Chen

In the chemical vapor deposition process, the reaction gas and precursor required for reaction that guided into the equipment for deposition on the surface of the substrate. Since the process relate to the flow field state and the temperature in the reaction chamber, before the process, the flow flied numerical simulation analysis inside the vacuum chamber is performed.The article discusses the changes and difference of flow field under the different conditions in the multidirectional chemical vapor deposition system, and according to the result to optimize the inner design of the chamber.

Growth of Two-dimensional Transition Metal Dichalcogenides Toward Development of Damage-free Transfer Technologies

Yu-Ren Peng, Ming-Jing Lu, Yu-Qi Huang, Yu-Lun Chueh

With the discovery of two-dimensional materials, their unique and fascinating properties have revealed the application potential of these materials, especially in their development over the decade. Two-dimensional transition metal dichalcogenides (TMDs) are one huge family in this field owing to their layered structures and tuning capabilities, and their applications, such as transistors, energy storage, or sensors, which are of interest to researchers. High-quality, large-area material growth methods based on chemical vapor deposition (CVD) have attracted much attention. The first section of the paper will focus on the growth of two-dimensional transition metal chalcogenides. Subsequently, it is usually still necessary to transfer 2D layered films to the target substrate for a follow-up study. The process is often accompanied by undesirable defects, such as residues, wrinkles, or bubbles, which impede the performance of the device by reducing its electron mobility. In the second section, we will discuss the 2D TMDs subsequent transfer technology and compare the advantages and disadvantages of different technologies.


ScxAl1-xN Piezoelectric Resonator Promising the Applications for 5G Millimeter Wave Communication System

Mau-Phon Houng, Jau-Wei Hung

The 5G wireless standards is a promising solution for the increasing number of bands and the complexity in the wireless communication system. Due to CMOS compatibility and well-developed techniques, AlN has been popular in the wireless communication system. However, limited piezoelectric coefficients, kt2, was observed in AlN films which affecting the bandwidth of the filter. Recent work shows an increase in kt2 values up to 4-5 times larger than AlN can be obtained by doping Sc into AlN, that means, ScxAl1-xN-base filters can be played as a potential device in the 5G era. For such a new material, some kinds of important challenges, such as, material growth Prameters, devices fabrication techniques, improve methods on device characteristics and the roles of ScxAl1-xN-base resonator applied on millimeter wave communication system and energy harvesting devices will be discussed

Applying Tunable Light Source with Monochromator for Calibration of Hyperspectral Imaging

Chao-Feng Liu, Yun-Chi Huang, Guo-Hao Lu, Chun-Jen Weng, Sheng-Lung Huang

This article will introduce how to build and adjust the tunable light source with monophotometer, and explain the principle and operation of the instrument used in this architecture. Through LabVIEW to write a human-machine control interface, this system is applied to the measurement of spectral response of the HSI camera. The experimental architecture uses tunable light source and optical components to establish a high-resolution system. The optical components include an adjustable slit, a focusing lens, an arc light source, and a filter. In this experiment, a spectrometer is used to measure the 600 nm emitted by the system. Finally, the optimized tunable light source in different wavelength bands is imported into a HSI camera to measure the spectral response in band 470-800 nm . It is observed that the FWHM of the HSI camera’s response is between 4 nm and 8 nm.

Heating Mechanisms of Magnetic Hyperthermia for Tumor Therapy

Chia-Wei Chang, Yen-Pei Lu, Ming-Fu Chen, Kun-Huan Wu, Hao-Ting Huang

Biologically targeted magnetic hyperthermia has been introduced clinically as an alternative therapy for the local treatment of tumors. Magnetic hyperthermia employs an alternating magnetic field to excite magnetic nanoparticles to generate heat to attack tumor cells. It has been proven to have many advantages, such as the ability to penetrate deep tissue for treatment, selectively attack tumor cells, and have a high biosafety. Compared with chemotherapy and radiotherapy, the side effects are relatively mild, and it will not cause a great burden on the body like surgery. In order to explore the potential and limits of targeted magnetic hyperthermia, it is necessary to further understand the heat generation mechanism and methods to improve the efficiency of tumor treatment.