scholarly journals Study for plasma etching of dielectric film in semiconductor device manufacturing. Review of ASET research project

2002 ◽  
Vol 74 (3) ◽  
pp. 381-395 ◽  
Author(s):  
Makoto Sekine

Conventional developments were conducted in a very empirical way, such as a trial and error with many speculations using qualitative data. This approach requires more and more resources and time for the development of future devices with a design rule below 100 nm in the system on a chip (SOC) era. It is necessary to establish a systematic methodology for process development and qualification. ASET Plasma Laboratory had been found to research a basis for the systematic development of the plasma etching technology. Fluorocarbon (CF) plasma for the etching of high-aspect-ratio contact holes in SiO2 was investigated intensively in the 5-year program that finished in March 2001. They introduced 5 plasma sources that can etch 0.1-mm contact holes on a 200-mm wafer in production, and state-of-the-art diagnostics tools for the plasma and etched surface. The SiO2 etch mechanism was revealed from the etch species generation to the reaction in a deep hole. The number of electron collisions to fluorocarbon gas molecule is proposed as an important parameter to control the gas dissociation and etch species flux to the surface. An etch reaction model was also proposed using the estimated-surface-reaction probability that is a function of ion energy and CF polymer thickness that reduces the net ion energy to the reaction layer. The CF polymer thickness was determined by a balance equation of generation term (radical fluxes) and loss terms (etching by ions, radicals, and out-flux oxygen from SiO2). A program was developed and successfully predicts the etch rates of Si-containing materials, including organic dielectrics. Requirements for the next-generation plasma etch tools are also discussed.

1996 ◽  
Vol 450 ◽  
Author(s):  
C. R. Eddy ◽  
D. Leonhardt ◽  
V. A. Shamamian ◽  
R. T. Holm ◽  
O. J. Glembocki ◽  
...  

ABSTRACTHigh density plasma etching of Hg1−xCdxTe in CH4/H2/Ar chemistry is examined using mass spectroscopy with careful surface temperature monitoring. The dominant etch products are monitored as a function of surface temperature (15–200°C), ion energy (20–200 eV), total pressure (0.5–5 mTorr), microwave power (200–400 W), and flow fraction of methane in the etch gas mixture (0–30%). In addition, observations are made regarding the regions of parameter space which are best suited to anisotropie, low damage etch processing. These observations are compared with previous results in the form of scanning electron micrographs of etched features for anisotropy evaluation and Hall effect measurements for residual damage. Insights to the overall etch mechanism are given.


1997 ◽  
Vol 468 ◽  
Author(s):  
F. Ren ◽  
J. R. Lothian ◽  
Y. K. Chen ◽  
J. D. Mackenzie ◽  
S. M. Donovan ◽  
...  

ABSTRACTDuring gate mesa plasma etching of InN/InAlN field effect transistors the apparent conductivity in the channel can be either increased through three different mechanisms. If hydrogen is part of the plasma chemistry, hydrogen passivation of the shallow donors in the InAlN can occur, we find diffusion depths for 2H of ≥ 0.5 micron in 30 mins at 200°C. The hydrogen remains in the material until temperatures ≥ 700°C Energetic ion bombardment in SF6/O2 or BCl/Ar plasmas also compensates the doping in the InAlN by creation of deep acceptor states. Finally the conductivity of the immediate InAlN surface can be increased by preferential loss of N during BCl3 plasma etching, leading to poor rectifying contact characteristics when the gate metal is deposited on this etched surface. Careful control of plasma chemistry, ion energy and stoichiometry of the etched surface are necessary for acceptable pinch-off characteristics.


Author(s):  
F. Banhart ◽  
F.O. Phillipp ◽  
R. Bergmann ◽  
E. Czech ◽  
M. Konuma ◽  
...  

Defect-free silicon layers grown on insulators (SOI) are an essential component for future three-dimensional integration of semiconductor devices. Liquid phase epitaxy (LPE) has proved to be a powerful technique to grow high quality SOI structures for devices and for basic physical research. Electron microscopy is indispensable for the development of the growth technique and reveals many interesting structural properties of these materials. Transmission and scanning electron microscopy can be applied to study growth mechanisms, structural defects, and the morphology of Si and SOI layers grown from metallic solutions of various compositions.The treatment of the Si substrates prior to the epitaxial growth described here is wet chemical etching and plasma etching with NF3 ions. At a sample temperature of 20°C the ion etched surface appeared rough (Fig. 1). Plasma etching at a sample temperature of −125°C, however, yields smooth and clean Si surfaces, and, in addition, high anisotropy (small side etching) and selectivity (low etch rate of SiO2) as shown in Fig. 2.


Author(s):  
DongKwon Jeong ◽  
JuHyeon Ahn ◽  
SangIn Lee ◽  
JooHyuk Chung ◽  
ByungLyul Park ◽  
...  

Abstract This paper presents the problems, the solutions, and the development state of the novel 0.18 μm Cu Metal Process through failure analysis of the Alpha CPU under development at Samsung Electronics. The presented problems include : “Via Bottom Lifting” induced by the Cu Via void, “Via Bottom dissociation” due to the IMD stress, “Via side dissociation” due to the poor formation of the Barrier Metal, “Via short/not-open failure” due to the IMD lifting, and Cu metal Corrosion/Loss. The analysis was carried out on the Via Contact Test Chain Patterns, using the “Electron (ION) Charge Up” method. After carefully analyzing each of the failure types, process improvement efforts followed. As a result, the pass rate of the via contact Rc was brought up from a mere 20% to 95%, and the device speed higher than 1.1 GHz was achieved, which surpasses the target speed of 1 GHz.


2020 ◽  
Vol 58 (6) ◽  
pp. 397-402
Author(s):  
Junyoung Park ◽  
Byoungmoon Oh ◽  
Kyongnam Kim

PFC gas is primarily used during the etching process in the manufacture of ULSIs and in cleaning after CVD processes. PFC is classified as a greenhouse gas that stays in the atmosphere for a long time and has a high GWP. High capacity and high integration have been achieved in recent years as semiconductor device structures have been replaced by vertical layer structures, and the consumption of PFC gas has exploded due to the increase in high aspect ratio and patterning processes. Therefore, many researchers have been working on methods to decompose, recover, and reuse the gas after the etching process to reduce the emissions of PFC gas. In this study, etching and recovery processes were performed using C5F8 in L-FC which is in liquid phase at room temperature. Among the L-FCs, C5F8 gas has a high C/F ratio, similar to that of the C4F8 gas, which is a conventional PFC gas. In addition, to confirm its reusability, the recovered C5F8 was injected back into the chamber, and the electron temperature, plasma density, and ion energy distribution were analyzed. Based on these experimental data, the reliability of the etch processes performed with recovered C5F8 gas was evaluated, and the possibility of reusing the recovered C5F8 gas was confirmed.


2000 ◽  
Vol 657 ◽  
Author(s):  
Junting Liu ◽  
Nikolay I. Nemchuk ◽  
Dieter G. Ast ◽  
J. Gregory Couillard

ABSTRACTMicro-machined transparent components are of interest for optical MEMS and miniaturized biological systems. The glass ceramic GC6 developed by Corning is optically transparent, has a softening point in excess of 900°C, and a thermal expansion coefficient matched to silicon. These properties make it useful for the construction of devices that combine thin film silicon electronics with MEMS systems.Both the ceramic precursor (green glass) and the glass ceramic etch at a similar rate, about 1/3 to 1/4 of that of SiO2 etched under the same conditions, indicating that chemistry rather than microstructure control the etch rate. The cleaning steps used to clean the glass precursor profoundly influence the degree of surface roughness that develops during subsequent plasma etching. In glass ceramics, the morphology of plasma etched surface is always very smooth and independent of the cleaning steps used. Assuming that the removal of spinel crystals is the rate limiting step in plasma etching glass ceramics can explain this observation.


1999 ◽  
Vol 4 (S1) ◽  
pp. 902-913 ◽  
Author(s):  
Charles R. Eddy

As III-V nitride devices advance in technological importance, a fundamental understanding of device processing techniques becomes essential. Recent works have exposed various aspects of etch processes. The most recent advances and the greatest remaining challenges in the etching of GaN, AlN, and InN are reviewed. A more detailed presentation is given with respect to GaN high density plasma etching. In particular, the results of parametric and fundamental studies of GaN etching in a high density plasma are described. The effect of ion energy and mass on surface electronic properties is reported. Experimental results identify preferential sputtering as the leading cause of observed surface non-stoichiometry. This mechanism provides excellent surfaces for ohmic contacts to n-type GaN, but presents a major obstacle for Schottky contacts or ohmic contacts to p-type GaN. Chlorine-based discharges minimize this stoichiometry problem by improving the rate of gallium removal from the surface. In an effort to better understand the high density plasma etching process for GaN, in-situ mass spectrometry is employed to study the chlorine-based high density plasma etching process. Gallium chloride mass peaks were monitored in a highly surface sensitive geometry as a function of microwave power (ion flux), total pressure (neutral flux), and ion energy. Microwave power and pressure dependencies clearly demonstrate the importance of reactive ions in the etching of wide band gap materials. The ion energy dependence demonstrates the importance of adequate ion energy to promote a reasonable etch rate (≥100-150 eV). The benefits of ion-assisted chemical etching are diminished for ion energies in excess of 350 V, placing an upper limit to the useful ion energy range for etching GaN. The impact of these results on device processing will be discussed and future needs identified.


Nanomaterials ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 936 ◽  
Author(s):  
Wei-Kai Wang ◽  
Yu-Xiu Lin ◽  
Yi-Jie Xu

Yttrium fluoride (YF3) films were grown on sapphire substrate by a radio frequency magnetron using a commercial ceramic target in a vacuum chamber. The structure, composition, and plasma etching behavior of the films were systematically investigated. The YF3 film was deposited at a working pressure of 5 mTorr and an RF power of 150 W. The substrate-heating temperature was increased from 400 to 700 °C in increments of 100 °C. High-resolution transmission electron microscopy (HRTEM) and X-ray diffraction results confirmed an orthorhombic YF3 structure was obtained at a substrate temperature of 700 °C for 2 h. X-ray photoelectron spectroscopy revealed a strongly fluorinated bond (Y–F bond) on the etched surface of the YF3 films. HRTEM analysis also revealed that the YF3 films became yttrium-oxyfluorinated after exposure to fluorocarbon plasma. The etching depth was three times lower on YF3 film than on Al2O3 plate. These results showed that the YF3 films have excellent erosion resistance properties compared to Al2O3 plates.


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