• Korean Chemical Engineering Research
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• v.51 no.6
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• pp.755-759
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• 2013

The etch rate and etch profile of Si was investigated when Ar was added to an $SF_6$ plasma in the etch step of the Bosch process. A Si substrate was etched with the Bosch process using $SF_6$ and $SF_6$/Ar plasmas, respectively, in the etch step to analyze the effects of Ar addition on the etch characteristics of Si. When the Ar flow rate in the $SF_6$ plasma was increased, the etch rate of the Si substrate increased, had a maximum at 20% of the Ar flow rate, and then decreased. This was because the addition of Ar to the $SF_6$ plasma in the etch step of the Bosch process resulted in the bombardment of Ar ions on the Si substrate. This enhanced the chemical reactions (thus etch rates) between F radicals and Si as well as led to sputtering of Si particles. Consequently, the etch rate was higher more than 10% and the etch profile was more anisotropic when the Si substrate was etched with the Bosch process using a $SF_6$/Ar (20% of Ar flow rate) plasma during the etch step. This work revealed a feasibility to improve the etch rate and anisotropic etch profile of Si performed with the Bosch process.

• Journal of Drive and Control
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• v.4 no.4
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• pp.59-62
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• 2007

• Journal of the Korea Academia-Industrial cooperation Society
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• v.5 no.2
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• pp.128-131
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• 2004

In this study Bosch etching process repeating etch and deposition by STS-ICP ASEHR was evaluated. Fundamentally etch depth changes were affected by thickness of deposited PR, $SiO_2$ and depth, and pattern size on the substrate. However etch rates were observed to be changed by variable parameters such as platen power, coil power, and process pressure. Etch rate showed $1.2\mu{m}/min$ and sidewall profile showed $90\pm0.2^\circ$ with platen power 12W, coil power 500W, and etch/passivation cycle 6/7sec. It was confirmed that this result was very typical to Bosch process utilizing ICP.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.17 no.7
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• pp.701-707
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• 2004

High aspect ratio silicon structure through deep silicon etching process have become indispensable for advanced MEMS applications. In this paper, we present the results of modified Bosch process to obtain anisotropic silicon structure with conventional Inductively Coupled Plasma (ICP) etcher instead of the expensive Bosch process systems. In modified Bosch process, etching step ($SFsub6$) / sidewall passivation ($Csub4Fsub8$) step time is much longer than commercialized Bosch scheme and process transition time is introduced between process steps to improve gas switching and RF power delivery efficiency. To optimize process parameters, etching ($SFsub6$) / sidewall passivation ($Csub4Fsub8$) time and ion energy effects on etching profile was investigated. Etch profile strongly depends on the period of etch / passivation and ion energy. Furthermore, substrate temperature during etching process was found to be an important parameter determining etching profile. Test structures with different pattern size have been etched for the comparison of the aspect ratio dependent etch rate and the formation of silicon grass. At optimized process condition, micropatterns etched with modified Bosch process showed nearly vertical sidewall and no silicon grass formation with etch rate of 1.2 ${\mu}{\textrm}{m}$/ min and the size of scallop of 250 nm.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.05e
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• pp.77-80
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• 2003

MEMS(Micro Electro Mechanical System) 기술에서 실리콘 식각기술의 중요성으로 플라즈마 식각기술의 개발이 꾸준히 진행되고 있다. 이중에서 ICP(Inductive Coupled Plasma)는 기존의 증착장치에 유도결합식 플라즈마를 추가로 발생시켜 증착막의 특성을 획기적으로 개선시키는 가장 최근에 개발된 기술이며, 이용에너지를 증가시키지 않고도 이용밀도를 높이고 이용업자들에 방향성을 가할 수 있는 새로운 플라즈마 기술로, 주로 MEMS 제조공정에 응용되고 있다. 본 연구에서는 STS-ICP $ASE^{HR}$을 이용하여 식각과 증착공정을 반복하여 식각을 하는 Bosch 식각에 관하여 연구하였다 STS-ICP $ASE^{HR}$ 장비의 Platen power, Coil power 및 Process pressure에 다양한 변화를 주어 각 변수에 따른 식각속도를 관찰하였다. 각 공정별 변수를 변화시킨 결과 Platen power 12W, Coil power 500W, 식각/Passivation Cycle 6/7sec 일 경우 식각속도는 $1.2{\mu}m$/min 이었고, Sidewall profile은 $90{\pm}0.7^{\circ}$로 나타나 매우 우수한 결과를 보였다.

• Proceedings of the Materials Research Society of Korea Conference
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• 2007.11a
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• pp.12.1-12.1
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• 2007

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.26 no.1
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• pp.65-75
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• 1990

There have been many methods for measuring the injection rate of diesel engines, but the results of them are not always identical and the reason for the discordance is not clear. Besides, a single shot injection equipment has been used for the fuel spray and the combustion research of diesel engines, but the results of experiment using the equipment don't apply to a volleyed shot injection of real engines. This paper investigates the merits and faults of the Bosch's method and the Zeuch's method, at the same, this paper also compares the injection rates of single shot inject rates of single shot injection and a volleyed shot injected by the Bosch's method. the results are summarized as follows: (1) The measurement error of the Bosch's method is about $\pm$1%, therefore, its accuracy is reliable. (2) By the Bosch's method, as the speed and the load of fuel pump increase, the injection rate becomes higher, on the contrary, the injection period(ms) shortens as the speed increases and the load decreases. (3) In this experiment, the injection rate of a single shot injection is lower than that of a volleyed shot injection under the same conditions. (4) The bulk modulus of elasticity using the Zeuch's method increases in proportion to the back pressure. (5) The Zeuch's method is less accurate than the Bosch's method.

• Proceedings of the KSRS Conference
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• 2004.10a
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• pp.3-6
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• 2004

This study aims to estimate, in monetary figures, the environmental value of recreational theme park- Huis Ten Bosch (HTB), located in Nagasaki Prefecture, Japan, through the integration of both contingent valuation method (CVM) and remote sensing. In the analysis, we have estimated the environmental value of HTB through CVM. Then, we have compared this amount with the valuation made by using remote sensing. The results of the study would provide the interest groups some monetary base, to value the worth of environmental restoration activities undertaken by HTB.

• Journal of the Korea Safety Management & Science
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• v.17 no.3
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• pp.355-362
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• 2015

There has been an increase of using Bosch Process to fabricate MEMS Device, TSV, Power chip for straight etching profile. Essentially, the interest of TSV technology is rapidly floated, accordingly the demand of Bosch Process is able to hold the prominent position for straight etching of Si or another wafers. Recently, the process to prevent under etching or over etching using EPD equipment is widely used for improvement of mechanical, electrical properties of devices. As an EPD device, the OES is widely used to find accurate end point of etching. However, it is difficult to maintain the light source from view port of chamber because of contamination caused by ion conflict and byproducts in the chamber. In this study, we adapted the SPOES to avoid lose of signal and detect less open ratio under 1 %. We use 12inch Si wafer and execute the through etching 500um of thickness. Furthermore, to get the clear EPD data, we developed an algorithm to only receive the etching part without deposition part. The results showed possible to find End Point of under 1 % of open ratio etching process.

• Korean Journal of Metals and Materials
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• v.49 no.10
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• pp.797-804
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• 2011

In this study, the mechanisms of the three steps (the polymer deposition step, the polymer etching step and the Si etching step) that constitute the Bosch process were investigated. The effects of radicals and ions on each step were quantitatively analyzed by comparing the simulated aspect ratio dependency of the deposition or etch rate with the experimental results. In the polymer deposition step, fluorocarbon polymer is deposited by chemical reactions of $CF_x$ radicals, of which the reaction probability is 0.13. Although the polymer etching step and the Si etching step were conducted under the same conditions, the etching mechanisms of polymer and Si were found to be quite different. In the polymer etching step, both chemical etching and physical sputter-etching contribute to the polymer etching. Whereas, in the Si etching step, Si is chemically etched by F radicals, of which the reactivity is greatly increased by the bombardment of energetic ions.