2012.12
About Instruments Today No. 191
Scanning Probe Microscopy
The Influence of Modulation Voltage in Scanning Capacitance Microscopy on the Observation of Electrical Junctions [ 下載 PDF ]
Chin-Wei Hu, Mao-Nan Chang, Tung-Huan Chou, Yao-Jen Lee
Scanning capacitance microscopy (SCM) can qualitatively provides the distribution of carrier concentrations and types, electrical junction depths, widths of depletion regions, channel lengths and the quality of a dielectric layer. In this article, we for the first time introduced a dark-mode SCM and demonstrated the influence of modulation voltage (MV) on SCM images of electrical junctions without photopertubation. Dark-mode SCM can avoid junction image distortion induced by photoperturbations, allowing us to take a close look at the role of MV on SCM images of electrical junctions. Our experimental results indicated that higher MV may narrow the observed junction regions and broaden the carrier distribution. Therefore, using lower MV in dark-mode SCM is a reliable approach to precise SCM measurements.
Magnetic Force Microscopy of High Aspect Ratio Magnetic Nano-Cylinder Structure [ 下載 PDF ]
Cheng-Yi Kuo, Yu-Chen Huang, Jong-Ching Wu
When the high aspect ratio of magnetic nano-cylinder structures are probed by magnetic force microscopy (MFM), the distorted images are often observed and yet the samples/tips are easily destructed mutually. In order to solve this problem, we report a technique of planarizing magnetic nano-cylinder array by spin-coating photoresist. The height difference of the nano-cylinder from the surrounding is greatly reduced and the corresponding magnetic images are successfully obtained. Due to the nature of a three-dimensional magnetic confi guration, it is obviously found that the intermediate state of the top end reveals two head-to-head and tail-to-tail transverse domain walls rather than a typical flux-closure vortex state in thin magnetic rings. The experimental results are well fitted with numerical simulations.
Application of Scanning Spreading Resistance Microscope for IC Industry [ 下載 PDF ]
KaiMin Yin, Shu-Cheng Chin
Although secondary ion mass spectrometry (SIMS) analysis provide good spatial resolution and wide dynamic range for IC industry on implantation engineering control, but it is only for 1D information. To observe high performance of 2D junction profiling of transistors is very important. Scanning spreading resistance microscopy (SSRM) has been shown to be the most promising candidate to provide the high resolution 2D carrier distributions and wide range of carrier concentrations. In this paper, the authors give the explanations about the principle of SSRM and why it can provide < 1 nm high spatial resolution information; meanwhile, we also introduce the most up to date of SSRM development in worldwide.
Non-Destructive Test of GaN Thin Film Grown on Patterned Sapphire Substrates by Using Scanning Near-Field Optical Microscope [ 下載 PDF ]
Liang-Chen Li, Chia-Tsung Chuang, Yu-Tai Sung, Yuen-Wuu Suen
We report the investigation of the defect distribution of GaN grown on patterned sapphire substrates by using a scanning near-field optical microscope (SNOM). A He-Cd laser (325 nm) or a green-light semiconductor laser (532 nm) was used as the light source in the SNOM system. The transmission SNOM images can be used to study the distribution of defects of a GaN LED structure on a patternned sapphire substrat. We found that the defects are located near the edge of the recess holes on sapphire, and the quality of the GaN thin film can be improved by adding random SiO2 blocking masks.
New Generation Imaging Technique of Atomic Force Microscope — PeakForce Tapping Mode and Relative Deviated Mode [ 下載 PDF ]
Hung Min Lin, Yen Fu Chen, Mark Chang
Using PeakForce Tapping could improve the drawback of the traditional AFM technique. In this article, we will explain how PeakForce tapping provides not only rapid quantitative nano-mechanics mapping but also automated feedback optimization of AFM imaging. This new technique is compatible with C-AFM and KPFM, and gains both of mechanics and electrical information in high spatial resolution simultaneously.
The Development of Organic Polymer Solar Cells [ 下載 PDF ]
Shiang Lan, Shang-Hong Lin, Ching-Fuh Lin
Human beings are facing an important problem of energy shortage. Due to the increasing oil price, several renewable energy sources are explored to fill the energy requirement gap between demand and supply. Polymer solar cells had been one of the most promising green energy technologies due to the possibility of achieving large-area, lightweight and flexible devices with low fabrication cost. To reach the goal of cell commercialization, three important aspects have to be considered. Efficiency, stability and production cost of the devices should be equally weighed in the development of polymer solar cells.
Principle of Optical Arbitrary Waveform Generation and Its Application in Millimeter-Wave Photonics [ 下載 PDF ]
Yi-Shiun Chen, Chen-Bin Huang
The basic construction and design principle of a Fourier-transform optical pulse shaper is explained. The fundamental limitation and distinction between conventional pulse shaping and optical arbitrary waveform generation are noted. The new aspects and the two necessary constituents of optical arbitrary waveform generations are described. In the last part, applications of optical arbitrary waveform generation in millimeter-wave photonics are discussed.
Prototype System Design of the Non-Contact Detection in Short-Circuits of PCB [ 下載 PDF ]
Chien-Hung Chen, Jyi-Jinn Chang, Kuo-Cheng Huang, Tai-Shan Liao, Chi-Hung Hwang
The short-circuit phenomenon is one common error in the operation of electronic circuit. Short-circuit will cause the electrical components damage and the incorrect function in PCB. In general, the detection of short-circuit is performed by using the electrode probe to contact each pad in single PCB or the probe card in mass production of PCD. Due to the fast development of circuit layout, the size of IC with pads is getting smaller; therefore, it is much diffi cult to detect short-circuit in PCB by the pads-contact inspection. This paper presents a method to detect shortcircuit area in PCB without the use of electrode probe, which employs the electromagnetic signals to sense and identify the change of electromagnetic induced by short-circuit.
8 Mega-Pixels Mobile Camera Design [ 下載 PDF ]
Wei-Jei Peng
Mobile phone with camera has become the standard function in recent years. Especially 8 mega-pixels camera is the primary specifi cation of high-level mobile, such as iPhone 5. In this paper, we design a 8 mega-pixels mobile camera by Zemax. From the beginning of optical specification, selecting sensor, introduction of plastic material and structure of first order, then we analyze this design by items used to evaluate the performance of mobile camera. Finally we make tolerance analysis to fit for practice manufacture.
