• Journal of the Semiconductor & Display Technology
• /
• v.14 no.3
• /
• pp.7-11
• /
• 2015

In order to protect the patterned mask from contamination during lithography process, pellicle has become a critical component for Extreme Ultraviolet (EUV) lithography technology. According to EUV pellicle requirements, the pellicle should have high EUV transmittance and robust mechanical property. In this study, silicon nitride, which is well-known for its remarkable mechanical property, was used as a pellicle membrane material to achieve high EUV transmittance. Since long silicon wet etching process time aggravates notching effect causing stress concentration on the edge or corner of etched structure, the remaining membrane is prone to fracture at the end of etch process. To overcome this notching effect and attain high transmittance, we began preparing a rather thick (200 nm) $SiN_x$ membrane which can be stably manufactured and was thinned into 43 nm thickness with HF wet etching process. The measured EUV transmittance shows similar values to the simulated result. Therefore, the result shows possibilities of HF thinning processes for $SiN_x$ EUV pellicle fabrication.

• Clean Technology
• /
• v.18 no.3
• /
• pp.280-286
• /
• 2012

The dry etching of sacrificial $SiO_2$ was performed in supercritical carbon dioxide. The etching of boron phosphor silica glass (BPSG), tetraethyl orthosilicate (TEOS), thermal $SiO_2$, and Si-nitride (SiN) was investigated by using a two chamber system with HF/py etchant and alcohol additives. The etch rate of sacrificial $SiO_2$ increased upon the addition of methanol. The etch selectivity of BPSG with respect to SiN was highest with IPA although the highest etch rate was resulted from methanol except BPSG. The etch rate increased with the temperature in HF/py/MeOH system. Especially the increase of the etch rate was much higher for BPSG with an increase in the reaction temperature. The etch residue was not reduced apparently upon the addition of alcohol cosolvents to HF/py. While the etch rate in HF/$H_2O$ was higher than HF/py/alcohol system, the rate decreased with the addition of alcohols to HF/$H_2O$. The cantilever beam structure of high aspect ratios was released by the dry ething in supercritical carbon dioxide without damage.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.56 no.2
• /
• pp.349-354
• /
• 2007

In this work, we investigated etching characteristics of $HfO_2$ thin film and Si using inductive coupled plasma(ICP) system. The ion energy distribution functions in an ICP system was analyzed by quadrupole mass spectrometer(QMS) with an electrostatic ion energy analyzer. The maximum etch rate of $HfO_2$ thin film is 85.5 nm/min at a $BCl_3/(BCl_3+Ar)$ of 20 % and decreased with further addition of $BCl_3$ gas. From the QMS measurements, the most dominant positive ion energy distributions(IEDS) showed a maximum at 20 % of $BCl_3$. These tendency was very similar to the etch characteristics. This result agreed with the universal energy dependency of ion enhanced chemical etching yields. And the maximum selectivity of $HfO_2$ over Si is 3.05 at a $O_2$ addition of 2 sccm into the $BCl_3/(BCl_3+Ar)$ of 20 % plasma.

• Proceedings of the KIEE Conference
• /
• 2006.10a
• /
• pp.117-118
• /
• 2006

In this work, we investigated etching characteristics of $HfO_2$ thin film and Si using inductive coupled plasma (ICP) system. The ion energy distribution functions in an inductively coupled plasma was analyzed by quadrupole mass spectrometer with an electrostatic ion energy analyzer. The maximum etch rate of $HfO_2$ is 85.5 nm/min at a $BCl_3/(BCl_3+Ar)$ of 20% and decreased with further addition of $BCl_3$ gas. From the QMS measurements, the most dominant positive ion energy distributions (IEDs) showed a maximum at 20 % of $BCl_3$. These tendency was very similar to the etch characteristics. This result agreed with the universal energy dependency of ion enhanced chemical etching yields. And the maximum selectivity of $HfO_2$ over Si is 3.05 at a O2 addition of 2 sccm into the $BCl_3/(BCl_3+ Ar)$ of 20% plasma.

• Journal of the Korean institute of surface engineering
• /
• v.49 no.3
• /
• pp.301-306
• /
• 2016

The effects of nanotexturing and post-etching on the reflection and quantum efficiency properties of diamond wire sawn (DWS) multicrystalline silicon (mc-Si) solar cell have been investigated. The chemical solutions, which are acidic etching solution (HF-$HNO_3$), metal assisted chemical etching (MAC etch) solutions ($AgNO_3$-HF-DI, HF-$H_2O_2$-DI) and post-etching solution (diluted KOH at $80^{\circ}C$), were used for micro- and nano-texturing at the surface of diamond wire sawn (DWS) mc-Si wafer. Experiments were performed with various post-etching time conditions in order to determine the optimized etching condition for solar cell. The reflectance of mc-Si wafer texturing with acidic etching solution showed a very high reflectance value of about 30% (w/o anti-reflection coating), which indicates the insufficient light absorption for solar cell. The formation of nano-texture on the surface of mc-Si contributed to the enhancement of light absorption. Also, post-etching time condition of 240 s was found adequate to the nano-texturing of mc-Si due to its high external quantum efficiency of about 30% at short wavelengths and high short circuit current density ($J_{sc}$) of $35.4mA/cm^2$.

• Korean Chemical Engineering Research
• /
• v.58 no.3
• /
• pp.474-479
• /
• 2020

The etching solution for slimming of glass substrates was manufactured and HF was used as the main ingredient of wet etching solutions. Various types of strong acids such as HCl, HNO₃, H₂SO₄, amino acids and carboxylic acids such as citric acid, and etched solutions, respectively, were used to measure the etching rates and changes in surface shape of the glass. Regardless of the type of strong acids, the etching rate of the glass increased linearly as the added amount increased, and the sludge removal effect of the glass surface was also shown. The etching solution containing HCl showed more efficient results than other strong acids in the etching rate and the effect of removing sludge. The addition of carboxylic acid did not significantly affect the variation of etching rate, but had the effect of removing sludge. However, if amino acids were added, changes in etching rate and sludge removal were not significant.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2005.10a
• /
• pp.182-185
• /
• 2005

Indentation pattern and line pattern were machined on borosilicate(Pyrex 7740 glass) surface using the combination of mechanical machining by $Nanoi-indenter\circledR$ XP and HF wet etching, and a etch-mask effect of the affected layer of the nano-scratched and indented Pyrex 7740 glass surface was investigated. In this study, effects of indentation and scratch process with etching time on the morphologies of the indented and scratched surfaces after isotropic etching were investigated from an angle of deformation energies.

• Journal of the Korean Electrochemical Society
• /
• v.16 no.1
• /
• pp.1-8
• /
• 2013

This review article summarizes metal-assisted chemical etching (MAC etch or MACE), an anisotropic etching method for Si, and describes principles, main factors, and recent achievements in literature. In 1990, it was discovered that, with metal catalyst on surface and $H_2O_2$/HF as etchant, Si substrate can be etched anisotropically, in even in solution. In contrast to high-cost vacuum-based dry etching methods, MAC etch enables to fabricate a variety of high aspect ratio nanostructures through wet etching process.

• Korean Journal of Materials Research
• /
• v.4 no.4
• /
• pp.379-384
• /
• 1994

Room-temperature photoluminescent porous Si has been formed by etching Si wafer u-ith the solution of $HF:HNO_{3}: H_{2}O$=l : 5 : 10. We have observed photoluminescence(PL) spectra similar to those reported recently for porous-Si films formed by anodic etching with HF solutions. We have also investigated the dependence of PI, spectra on the etching time which was varied from 1 to 10 minutes. We found that 5-minute etching gave us the strongest PL intensity. We also found by atomic force microscopy( AFM) measurements that the surface fearure size became smaller for longer etching time and the average feature size of the etched Si wafer for 5-minute was about 1, 500~2, 000$\AA$. This indicates that the surface feature of the etched porous Si affects the PL intensity of the sample.

• Proceedings of the IEEK Conference
• /
• 2006.06a
• /
• pp.551-552
• /
• 2006

Plasma-induced charging damage was been measured during TaN gate electrode of MISFET(TaN/$HfO_2$/Si) or interconnection metal etching step using large antenna structures. The results of these experiments were obtained that $HfO_2$ gate dielectric layer was affected about plasma charging effects and damage increased with F-N tunneling. Therefore, the etching conditions should be optimized to avoid the defects caused by plasma charging.