• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2001년도 하계학술대회 논문집
• /
• pp.279-282
• /
• 2001

The IBE(ion beam etching)-induced Schottky barrier variation which depends on various etching history related with ion energy, incident angle and etching time has been investigated using voltage-current, capacitance-voltage characteristics of metal-etched silicon contact and morphology of etched surface were studied using AFM(atomic force microscope). For ion beam etched n-type silicons, Schottky barrier is reduced according to ion beam energy. It can be seen that amount of donor-like positive charge created in the damaged layer is proportional to the ion energy. By contrary, for ion beam etched p-type silicons, the Schottky barrier and specific contact resistance are both increased. Not only etching time but also incident angle of ion beam has an effect on barrier height. Taping-mode AFM analysis shows increased roughness RMS(Root-Mean-Square) and depth distribution due to ion bombardment. Annealing in an N$_2$ ambient for 30 min was found to be effective in improving the diode characteristics of the etched samples and minimum annealing temperatures to recover IBE-induced barrier variation were related to ion beam energy.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2005년도 추계학술대회 논문집 Vol.18
• /
• pp.338-339
• /
• 2005

The wider surface of the aluminum foil, electrochemically very important and it is necessary to increase the surface area. A study has been made of the fabrication condition for etching cube texture of high purity aluminium foil and of electrochemical etching of the aluminium foil. In the present work, it is shown there exists a relation between the influence of the pre-treatment time in the NaOH & HCI solution and $H_2SO_4$ concentration in the conversion solution. Also effect of temperature during AC etching was also studied. Result of the etched aluminum film is shown in the typical SEM images. Its electrochemical characteristics were investigated by cyclic voltammetry. And effects of current density and frequency is also reported. Cyclic voltammogram showed that the protective oxide film was formedon the inner surfaces of etch pit. the frequency influence resistance of oxide film in AC etching.

• 한국표면공학회지
• /
• 제27권3호
• /
• pp.158-165
• /
• 1994

Cu-Cr alloy thin film requires good quality of etching be used for TAB technology. The etched cross sec-tion was clean enough when the etching was performed in 0.1M $FeCl_3$ solution at $50^{\circ}C$. The etching rate was increased with the amount of $KMnO_4$. For enhanced profile of cross section and rate, the spray etchning was found to be superior compared to the immersion etching. A series of experiments were performed to improve the uniformity of the current distribution in electrodeposition onto the substrate with lithographic patterns. Copper was electrodeposited from quiescent-solution, paddle-agitated-solution, and air-bubbled-solution to in-vestigate the effect of the fluid flow. The thickness profile of the specimen measured by profilmetry has the non uniformity at feature scale in quiescent-solution, because of the longitudinal vortex roll caused by the natural convection. However, uniform thickness profile was achieved in paddle-agitated or air bubbled solu-tion.

• 한국표면공학회지
• /
• 제32권3호
• /
• pp.416-422
• /
• 1999

The characteristics of inductively coupled Cl$_2$/BCl$_3$ plasmas during the GaN etching were studied using plasma mass spectrometry by measuring the relative amounts of reactive ions, neutrals, and etch products. GaN etch rates increased with the increase of pressure and showed a maximum near 25mTorr for the pure $Cl_2$ and near 30mTorr for $Cl_2$$BCl_3$. The addition of$ BCl_3$ to $Cl_2$ also was increased GaN etch rates until 50%BCl$_3$ was mixed to $Cl_2$. The GaN etching with pure $Cl Cl_2$ appears to be related to the combination of Cl$_2^{+}$ ion bombardment and the chemical reaction of Cl radicals. In the case of the GaN etching with Cl$_2$/BCl$_3$, in addition to the combined effect of$_2^{ +}$ ions and Cl radicals, $_BCl2^{+ }$ ions appear to be responsible for some of GaN etching even though they do not have significant effect on the GaN etching compared to $Cl_2^{+}$ and Cl. $Ga^{+ }$ , $GaCl^{+}$ , $GaCl_2^{+}$ , and $N_2^{+}$ were observed as the positive ions of etch products, and the intensities of these etch products showed the same trends as those of GaN etch rate. Among the etch products, Ga and $N_2$ appear to be the main etch products.

• 한국자기학회:학술대회 개요집
• /
• 한국자기학회 2002년도 춘계연구발표회 논문개요집
• /
• pp.52-53
• /
• 2002

• 한국치위생학회지
• /
• 제1권2호
• /
• pp.251-260
• /
• 2001

The purpose of this article was to compare the fluoridation effect via individual tray with other professional methods. In oder to compare the fluoridation effect, 40 extracted human teeth was divided into 4 groups(each group was composed of 10 teeth) and the surface hardness of each group was tested in untreated, after fluoridation, after fluoridation and etching by 10% lactic acids. group I: no fluoridation(control) group II : fluoridation with 123%APF group III : fluoridation by iontophoresis with 2% NaF group IV : fluoridation by individual tray with 4% SnF2 gel Surface hardness was measured with Micro hardness tester(Shimadzu Co. Japan), Data analysis was conducted using the repeated measures ANOVA test. The results were as follows: 1. Four tested groups demonstrated nearly the same SMH in extracted state. 2. The SMH after fluoridation showed $330.57{\pm}139.09kg/mm^2$ in group IV, $221.79{\pm}187.48kg/mm^2$ in group II, $186.43{\pm}53.13kg/mm^2$ in group III. So the SMH of group IV, II were was significantly increased(p<0.01). 3. The SMH of group II, III, IV after acid etching was higher than the control group(p<0.01). 4. The SMH between group II, III, and IV after acid etching was not different significantly.

• 대한기계학회논문집A
• /
• 제32권5호
• /
• pp.424-429
• /
• 2008

Surface wettability in terms of the size of the micro nano structures has been examined. To evaluate the influence of the nano structures on the contact angles, we fabricated two different kinds of structures: squarepillar-type microstructure with nano-protrusions and without nano-protrusions. Microstructure and nanostructure arrays were fabricated by deep reactive ion etching (DRIE) and reactive ion etching (RIE) processes, respectively. And plasma polymerized fluorocarbon (PPFC) was finally deposited onto the fabricated structures. Average value of the measured contact angles from microstructures with nanoprotrusions was $6.37^{\circ}$ higher than that from microstructures without nano-protrusions. This result indicates that the nano-protrusions give a crucial effect to increase the contact angle.

• The Journal of Advanced Prosthodontics
• /
• 제12권5호
• /
• pp.273-282
• /
• 2020

PURPOSE. To assess shear bond strengths (SBS) of resin composites on aged and non-aged prosthetic materials with various surface treatments. MATERIALS AND METHODS. Cerasmart (CE), Vita Enamic (VE), Vita Mark II (VM), and IPS e.max CAD (EC) blocks were sliced, and rectangular-shaped specimens (14 × 12 × 1.5 mm; N = 352) were obtained. Half of the specimens were aged (5000 thermal cycles) for each material. Non-aged and aged specimens were divided into 4 groups according to the surface treatments (control, air abrasion, etching, and laser irradiation; n = 11) and processed for scanning electron microscopy (SEM). The repair procedure was performed after the surface treatments. SBS values and failure types were determined. Obtained data were statistically analyzed (P≤.05). RESULTS. The material type, surface treatment type, and their interactions were found significant with regard to SBS (P<.001). Aging also had a significant effect on prosthetic material-resin composite bonding (P<.001). SBS values of non-aged specimens ranged from 12.16 to 17.91 MPa, while SBS values of aged specimens ranged from 9.46 to 15.61 MPa. Non-aged VM in combination with acid etching presented the highest score while the control group of aged CE showed the lowest. CONCLUSION. Etching was more effective in achieving durable SBS for VM and EC. Laser irradiation could be considered as an alternative surface treatment method to air abrasion for all tested materials. Aging had significant effect on SBS values generated between tested materials and resin composite.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2004년도 추계학술대회 논문집
• /
• pp.351-354
• /
• 2004

This work presents a simple and cost-effective approach for maskless fabrication of positive-tone silicon master for the replica molding of hyperfine elastomeric channel. Positive-tone silicon masters were fabricated by a maskless fabrication technique using the combination of nanoscratch by Nanoindenter ⓡ XP and XOH wet etching. Grooves were machined on a silicon surface coated with native oxide by ductile-regime nanoscratch, and they were etched in a 20 wt％ KOH solution. After the KOH etching process, positive-tone structures resulted because of the etch-mask effect of the amorphous oxide layer generated by nanoscratch. The size and shape of the positive-tone structures were controlled by varying the etching time (5, 15, 18, 20, 25, 30 min) and the normal loads (1, 5 mN) during nanoscratch. Moreover, the effects of the Berkovich tip alignment (0, 45$^{\circ}$) on the deformation behavior and etching characteristic of silicon material were investigated.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 1997년도 춘계학술대회 논문집
• /
• pp.23-26
• /
• 1997

This work presents the TMAH/IPA anisotropic etching characteristics with addition of Pyrazine. (100) Si etching rate of 0.747 ${\mu}{\textrm}{m}$/min at 8$0^{\circ}C$ was obtained using TMAH 25 wt.% / IPA 17 vol.% / pyrazine 0.1 g. The etching rate of (100) Si is increased about 52% compare to pure TMAH 25 wt.%. But etching rate of (100) Si is decreased with increasing Pyrazine additive. Activation energy of TMAH/IPA/pyrazine is much lower than TMAH and TMAH/IPA solutions. Addition of Pyrazine does not effect on surface flatness and decreases undercutting ratio about 20 %. Therefore, TMAH/IPA/pyrazine is an attractive anisotropic etchant because of alkaline-ion free.