Microwave Imaging of Conductivity Distribution of Silicon Wafers

2003 ◽  
Author(s):  
Yang Ju ◽  
Masumi Saka ◽  
Hiroyuki Abe´
Keyword(s):  
Reflection Coefficient ◽  
Silicon Wafer ◽  
Spatial Resolution ◽  
Coaxial Line ◽  
Microwave Imaging ◽  
Silicon Wafers ◽  
Microwave Signal ◽  
Network Analyzer ◽  
Conductivity Distribution

Conductivity of silicon wafers was measured using the amplitude of the reflection coefficient of a microwave signal. A network analyzer was used to generate the microwave signal fed to a sensor and to measure the amplitude of the reflection coefficient. An open-ended coaxial line sensor was used to increase the spatial resolution and the sensitivity of the measurement. By microwave imaging, the distribution of the conductivity of a silicon wafer was mapped.

Microwave Imaging for the Integrity Assessment of IC Packages

2000 ◽  
Vol 123 (1) ◽  
pp. 42-46 ◽  
Author(s):  
Y. Ju ◽  
M. Saka ◽  
H. Abe´
Keyword(s):  
Reflection Coefficient ◽  
Imaging Technique ◽  
Coaxial Line ◽  
Dielectric Materials ◽  
Microwave Imaging ◽  
Promising Technique ◽  
Factors Affecting ◽  
Integrity Assessment ◽  
Soldering Process ◽  
Effective Reflection Coefficient

Since IC packages have been made thinner and smaller, the delamination and crack, which may be induced in the soldering process, have become important factors affecting the reliability of the package. The ability to penetrate deeply inside dielectric materials, and to reflect completely at the metal surface makes microwave inspection very suitable to detect such delamination. The authors have recently developed a new microwave imaging technique that uses an open-ended coaxial line sensor to detect the delamination in IC packages. The image was created by measuring the phase of the effective reflection coefficient at the aperture of the coaxial line sensor. For better evaluation of the shape and the size of the delamination, a method to further increase the spatial resolution of microwave imaging was studied in the present paper. The resolution affected by the dimensions of the sensor, the frequency of operation, and the standoff distance between the sensor and the sample was investigated by experiment. The experimental results indicate that microwave imaging is a promising technique for the integrity assessment of IC packages.

scholarly journals The Influence of Wire Speed on Phase Transitions and Residual Stress in Single Crystal Silicon Wafers Sawn by Resin Bonded Diamond Wire Saw

Micromachines ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 429
Author(s):  
Tengyun Liu ◽  
Peiqi Ge ◽  
Wenbo Bi
Keyword(s):  
Residual Stress ◽  
Surface Layer ◽  
Phase Transitions ◽  
Single Crystal ◽  
Amorphous Silicon ◽  
Silicon Wafer ◽  
Single Crystal Silicon ◽  
Silicon Wafers ◽  
Crystal Silicon ◽  
Diamond Wire

Lower warp is required for the single crystal silicon wafers sawn by a fixed diamond wire saw with the thinness of a silicon wafer. The residual stress in the surface layer of the silicon wafer is the primary reason for warp, which is generated by the phase transitions, elastic-plastic deformation, and non-uniform distribution of thermal energy during wire sawing. In this paper, an experiment of multi-wire sawing single crystal silicon is carried out, and the Raman spectra technique is used to detect the phase transitions and residual stress in the surface layer of the silicon wafers. Three different wire speeds are used to study the effect of wire speed on phase transition and residual stress of the silicon wafers. The experimental results indicate that amorphous silicon is generated during resin bonded diamond wire sawing, of which the Raman peaks are at 178.9 cm−1 and 468.5 cm−1. The ratio of the amorphous silicon surface area and the surface area of a single crystal silicon, and the depth of amorphous silicon layer increases with the increasing of wire speed. This indicates that more amorphous silicon is generated. There is both compressive stress and tensile stress on the surface layer of the silicon wafer. The residual tensile stress is between 0 and 200 MPa, and the compressive stress is between 0 and 300 MPa for the experimental results of this paper. Moreover, the residual stress increases with the increase of wire speed, indicating more amorphous silicon generated as well.

Experimental investigation into polishing of monocrystalline silicon wafer using double-disc chemical assisted magnetorheological finishing process

2021 ◽  
pp. 095440622098384
Author(s):  
Mayank Srivastava ◽  
Pulak M Pandey
Keyword(s):  
Surface Roughness ◽  
Silicon Wafer ◽  
Flow Rate ◽  
Silicon Wafers ◽  
Monocrystalline Silicon ◽  
Slurry Flow ◽  
Magnetorheological Finishing ◽  
Finishing Process ◽  
Process Factors ◽  
Slurry Flow Rate

In the present work, a novel hybrid finishing process that combines the two preferred methods in industries, namely, chemical-mechanical polishing (CMP) and magneto-rheological finishing (MRF), has been used to polish monocrystalline silicon wafers. The experiments were carried out on an indigenously developed double-disc chemical assisted magnetorheological finishing (DDCAMRF) experimental setup. The central composite design (CCD) was used to plan the experiments in order to estimate the effect of various process factors, namely polishing speed, slurry flow rate, percentage CIP concentration, and working gap on the surface roughness ([Formula: see text]) by DDCAMRF process. The analysis of variance was carried out to determine and analyze the contribution of significant factors affecting the surface roughness of polished silicon wafer. The statistical investigation revealed that percentage CIP concentration with a contribution of 30.6% has the maximum influence on the process performance followed by working gap (21.4%), slurry flow rate (14.4%), and polishing speed (1.65%). The surface roughness of polished silicon wafers was measured by the 3 D optical profilometer. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) were carried out to understand the surface morphology of polished silicon wafer. It was found that the surface roughness of silicon wafer improved with the increase in polishing speed and slurry flow rate, whereas it was deteriorated with the increase in percentage CIP concentration and working gap.

A Precision Alignment Method to <100> Direction on (110) Silicon Wafer

2001 ◽  
Author(s):  
Fan-Gang Tseng ◽  
Kai-Chen Chang
Keyword(s):  
Silicon Wafer ◽  
Crystal Orientation ◽  
Silicon Wafers ◽  
Innovative Approach ◽  
Alignment Accuracy ◽  
Alignment Method

Abstract This paper proposes a novel pre-etch method to determine the lt;100gt; direction on (110) silicon wafers for bulk etching. Series of circular windows were arranged in an arc of radius 48.9 mm, and bulk-etched to form hexagonal shapes for crystal orientation finding. The corners of the hexagons can be used as an alignment reference for the indication of the lt;100gt; direction on (110) silicon wafers. This innovative approach has been demonstrated experimentally to give an orientation-alignment accuracy of ± 0.03° for (110) wafers with 4-inch diameter.

scholarly journals Calculation of a non-reflective connection in a coaxial line

2021 ◽  
Vol 29 (1) ◽  
pp. 99-104
Author(s):  
V. M. Morozov ◽  
V. I. Magro
Keyword(s):  
Integral Equation ◽  
Reflection Coefficient ◽  
Coaxial Line ◽  
Integral Equation Method ◽  
Coaxial Waveguide ◽  
Equation Method ◽  
System Of Equations ◽  
T Wave ◽  
Significant Difference ◽  
Coaxial Lines

The calculation of the non-reflective connection in the coaxial line is performed by the integral equation method. The connection of coaxial lines with a significant difference in geometric dimensions is considered. A system of equations is obtained that allows calculating the reflection coefficient of the T-wave from such an inhomogeneity. This technique makes it possible to calculate a multistage coaxial waveguide in order to minimize the reflection coefficient from inhomogeneities.

WIDEBAND JEAN ANTENNA WITH BENDING STRUCTURE FOR MICROWAVE IMAGING APPLICATIONS

2016 ◽  
Vol 78 (6-2) ◽  
Author(s):  
Roshayati Yahya ◽  
Muhammad Ramlee Kamarudin ◽  
Norhudah Seman ◽  
Ali Moradikordalivand
Keyword(s):  
Reflection Coefficient ◽  
Normal Condition ◽  
Coplanar Waveguide ◽  
Microwave Imaging ◽  
Radiation Characteristics ◽  
Body Effect ◽  
Expected Frequency ◽  
Design Evolution ◽  
Bending Effect ◽  
Feeding Structure

In this paper, a wideband jean antenna with bending structure for flexible microwave imaging applications is presented. Coplanar waveguide (CPW) feeding structure with Koch shape ground slotted technique has been implemented for widening the bandwidth. The design evolution process of the proposed antenna is started from a simple CPW-fed monopole antenna to bending circumstance. The proposed antennas under normal condition, bending circumstance and as well as on-arm bending effect are simulated and optimized using CST microwave studio software and fabricated; also tested so as to validate the results . Under normal condition, the antenna provides measured bandwidth of 4500 MHz (1.5–6 GHz) in the case of |S11|≤−10 dB while 4360 MHz (1.44–5.8 GHz) for the measured bandwidth under bending circumstance is obtained. Also, there is a slight degradation on the reflection coefficient of the antenna under on-arm bending so that measured bandwidth became narrower with operating frequency of 3800 MHz (2.2–6 GHz). The measured gain of the antenna fluctuates between 2.5–5.6 dBi and 1.5–2.8 dBi with quasi-omnidirectional pattern within the expected frequency band for normal and bending condition, respectively. The proposed antenna provides a good performance in terms of its reflection coefficient and radiation characteristics. Therefore, due to insensitiveness to bending and body effect, the proposed antenna has become good candidate for microwave imaging applications.

scholarly journals A Tomograph Prototype for Quantitative Microwave Imaging: Preliminary Experimental Results

2018 ◽  
Vol 4 (12) ◽  
pp. 139 ◽  
Author(s):  
Alessandro Fedeli ◽  
Manuela Maffongelli ◽  
Ricardo Monleone ◽  
Claudio Pagnamenta ◽  
Matteo Pastorino ◽  
...  
Keyword(s):  
Ad Hoc ◽  
Microwave Imaging ◽  
Experimental Results ◽  
Network Analyzer ◽  
Reconstruction Algorithms ◽  
Quantitative Reconstruction ◽  
Qualitative And Quantitative ◽  
Switching Matrix ◽  
3D Printed ◽  
Transmission Measurements

A new prototype of a tomographic system for microwave imaging is presented in this paper. The target being tested is surrounded by an ad-hoc 3D-printed structure, which supports sixteen custom antenna elements. The transmission measurements between each pair of antennas are acquired through a vector network analyzer connected to a modular switching matrix. The collected data are inverted by a hybrid nonlinear procedure combining qualitative and quantitative reconstruction algorithms. Preliminary experimental results, showing the capabilities of the developed system, are reported.

Sign in / Sign up

Export Citation Format

Share Document