Cost-effective equipment for surface pre-treatment for cleaning and excitation of substrates in semiconductor technology

Abstract

This article presents a cost-effective ultraviolet-ozone cleaner (UV/O3 Cleaner) for surface pre-treatment of substrates in the field of semiconductor technology. The cleaner consists of two chambers, the upper one contains the electronics, including the time counter. The lower chamber contains the two UV sterilisation lamps and a UV reflector of anodized aluminium, which confines the area of high Ozone concentration in the area of interest. The device is successfully used for surface cleaning and modification of different materials. To this end, the two important wavelengths 253.7 nm (excitation of organic residues) and 184.9 nm (production of ozone from the atmospheric environment as a strong oxidant) were first detected. The effectiveness of UV/O3 cleaning is demonstrated by improving the properties of indium tin oxide (ITO) for OLED fabrication. The contact angle of water to ITO could be reduced from 90° to 3° and for diiodomethane, it was reduced from 55° to 31° within the 10 min of irradiation. This greatly improved wettability for polar and non-polar liquids can increase the flexibility in further process control. In addition, an improvement in wettability is characterized by measuring the contact angles for titanium dioxide (TiO2) and polydimethylsiloxane (PDMS). The contact angle of water to TiO2 decreased from 70° to 10°, and that of diiodomethane to TiO2 from 54° to 31°. The wettability of PDMS was also greatly increased. Here, the contact angle of water was reduced from 109° to 24° and the contact angle to diiodomethane from 89° to 49°. Article Highlights We report a cost-effective dry-cleaning device for surface cleaning and modification based on ultraviolet-ozone irradiation. Contact angle measurements show an increase of wettability for different materials due to surface modification. The UVO3 pre-treatment improves layer formation and optoelectrical properties of OLEDs.

New Formulas for Evaluation of Cyclohexanol Solidification on Substrates with Surface Nanostructures

“…The observational procedure is detailed as follows. UV treatment of the Si substrate for 20 min to remove organic matter Application of 250 μL of cyclohexanol onto each substrate, equivalent to a 500 μm film thickness (the liquid film covers the entire coupon surface to avoid wetting effects). Nitrogen inflow into the atmosphere control box at approximately 3 L/min. Commencement of recording. Activation of the light-emitting diode; concurrent initiation of temperature data logging for synchronization. 6Sequential Peltier temperature control: Sustaining a temperature of 28 °C, exceeding the melting point of 23 °C, for 1 min. Cooling to below the melting point at specified rates (3 °C with a holding time of 3 min). Increasing the temperature to 28 °C at a rate of 100 °C/min for remelting the sublimation agent. Termination of recording. …”

“… UV treatment of the Si substrate for 20 min to remove organic matter. 32 Application of 250 μL of cyclohexanol onto each substrate, equivalent to a 500 μm film thickness (the liquid film covers the entire coupon surface to avoid wetting effects). Nitrogen inflow into the atmosphere control box at approximately 3 L/min.…”

“…1 UV treatment of the Si substrate for 20 min to remove organic matter. 32 Crystal Counting Method. Subsequently, the captured videos were subjected to a meticulous temporal analysis to quantify the variations in the number of emerging crystal nuclei.…”

Kinetics formulation for Two-Dimensional Growth Behavior of Water/Ice Interface on Si Substrate

“…Here, ultraviolet (UV) treatment was performed for 20 min to clean the Si substrate surface by removing organic matter from it. The short-wavelength UV light energy broke the bonds of organic contaminants on the substrate surface, and simultaneously, active oxygen (O-) separated from the ozone generated by the UV light chemically bonds with the organic contaminants and decomposed them into volatile substances such as CO 2 and water, which were then removed, thereby cleaning the surface . Subsequent to this, 250 μL of water was dispensed onto each of the two substrates, yielding a film thickness of approximately 500 μm.…”

“…The short-wavelength UV light energy broke the bonds of organic contaminants on the substrate surface, and simultaneously, active oxygen (O-) separated from the ozone generated by the UV light chemically bonds with the organic contaminants and decomposed them into volatile substances such as CO 2 and water, which were then removed, thereby cleaning the surface. 28 Subsequent to this, 250 μL of water was dispensed onto each of the two substrates, yielding a film thickness of approximately 500 μm. For creating a regulated environment, nitrogen (N 2 ) was introduced into the atmosphere control box at a flow rate of approximately 1 LM.…”