Jerzy Ruzyllo

Mist fabrication of light emitting diodes with colloidal nanocrystal quantum dots

In this letter, we report a mist-deposition process for the assembly and patterning of nanocrystal quantum dots (NQDs) during the fabrication of quantum dot light emitting diodes (QD-LEDs), which allows for tight controls over the thickness, surface morphology, composition, and resolution of NQD emissive layers. A defect-free featuring uniform brightness QD-LED containing a mist-deposited emissive CdSe(ZnS) NQD layer was demonstrated. Additionally, the technique of successive mist deposition of multicolor NQDs through a set of registered shallow masks was employed to create a 6×6 matrix of alternating pixels composed of 5nm diameter CdSe(ZnS) NQDs (green) and 8nm diameter CdSe(ZnS) NQDs (red) on the same substrate. The results obtained demonstrate the potential of mist-deposition technology in the future development of full-color QD-LED displays.

Colloidal nanocrystal-based light-emitting diodes fabricated on plastic toward flexible quantum dot optoelectronics

We report the first demonstration of mechanically flexible quantum dot light-emitting-diodes (QD-LEDs) of all three RGB primary colors. The efficiencies of the flexible devices are high, suggesting the intrinsic flexibility of the QD-based optoelectronic devices.

Etching of Thermal Oxides in Low Pressure Anhydrous HF / CH 3 OH Gas Mixture at Elevated Temperature

Etching of thermal oxides in HF/CH 3 OH gas mixture at the pressure from 100 to 500 Torr and wafer temperatures from 25 to 120 o C is studied using a commercial cluster tool compatible reactor. Pressure and temperature are selected to control condensation of reactants on the etched surfaces, and hence, the thermal oxide etch rate. Using this etching mode, controlled etching of thermal oxides at rates up to 200 A/min was achieved without any water vapor intentionally added to the input gases

Atomic oxygen and the thermal oxidation of silicon

Both molecular and atomic oxygen have been postulated to react with silicon in the thermal oxidation process. At temperatures below 700 °C very little film growth is observed in molecular oxygen. When silicon is allowed to react thermally with a flowing afterglow containing atomic oxygen an enhancement in film growth is observed. Film growth in this mode exhibits little temperature activation and is speculated to be due to a constant concentration of atomic oxygen.

Reduced Pressure Etching of Thermal Oxides in Anhydrous HF / Alcoholic Gas Mixtures

Reduced pressure etching of thermal oxide in anhydrous HF gas with three different alcoholic solvent vapors is studied. Thermal oxide etch rates as functions of temperature, pressure, time, and HF partial pressure are presented for methanol, ethanol-water azeotrope (95.6% ethanol, 4.4% water), and 2-propanol (isopropyl alcohol). The etch rates are interpreted in terms of alcohol vapor pressure, HF ionization, and reaction product desorption. The efficient desorption of reaction products compared to vapor HF/H 2 O is believed to be responsible for both the wider process window for alcoholic solvents and the alleviation of the solid residue formation problem. Among the alcoholic solvents studied, methanol has the best potential while 2-propanol can also be useful in selected applications

Mist deposited high-k dielectrics for next generation MOS gates

Abstract This paper presents the results of the characterization of high-k dielectric films deposited by liquid source misted chemical deposition in a cluster tool for advanced MOS gates. Electrical characterization was performed in conjunction with atomic force microscopy and transmission electron microscopy. It was determined that not all compositions investigated are equally compatible with mist deposition. The effects of in situ surface conditioning prior to deposition were also examined. Among processes investigated the sequence depositing SrTa2O6 on a nitrided oxide interlayer grown by a UV/NO process showed the best promise.

Nearly isotropic etching of 6H‐SiC in NF3 and O2 using a remote plasma

Nearly isotropic etching of the 6H‐SiC carbon face has been achieved in a remote plasma at 330 °C using a mixture of O2 and NF3 in argon. Using evaporated aluminum as a mask, undercutting has been observed to a distance equal to the etch depth. The etch rate is a function of the ratio of O2 to NF3 flow rates and of temperature, peaking strongly to 220 nm/min at 82% oxygen for 330 °C. Smooth surfaces were obtained for gas ratios leading to the maximum etch rate, and also for a NF3‐argon mixture, with significant roughening observed for other O2‐NF3‐argon mixtures. In the absence of a practical wet etch for SiC, this procedure is promising for isotropic etching in SiC device processing.

Surface dopant concentration monitoring using noncontact surface charge profiling

This study is concerned with variations of the concentration of active boron dopant in the near surface region of silicon wafers. Boron can be deactivated by pairing with hydrogen or metals, particularly Cu and Fe, all of which may originate from the surface polishing process. The temperature dependence of boron activation is studied using the surface charge profiling method. Based on the determined activation energy of 1.28 eV it was concluded that in the p-type wafers used in this study initially observed boron deactivation was dominated by its interaction with hydrogen introduced during wafer polishing.

On the capacitance of metal/high-k dielectric material stack/silicon structures

Abstract The accumulation capacitance of metal–insulator–Si capacitors with SrTa 2 O 6 , ZrSiO 4 -based high- k gate dielectrics is observed to have significantly different dependence on the temperature and the frequency of a capacitance–voltage measurement than that of the conventional metal–oxide–Si capacitors. It is shown that this is due to contributions from the, often, inadvertently grown, and relatively poorer quality interfacial dielectric between the high- k material stack and the Si substrate.

Evaluation of thin oxides grown by the atomic oxygen afterglow method

This paper discusses the basic electrical properties of thin, less than 200 Å, films of silicon dioxide grown on silicon by a microwave plasma atomic oxygen afterglow method. This method of remote plasma oxidation of silicon allows gate oxides to be grown at temperatures as low as 400° C, and hence, is possibly attractive in VLSI/ULSI applications. Electrical properties of studied oxides depend strongly upon the composition of the discharge gas. The use of nitrogen as an oxygen diluent has an adverse impact on the fixed oxide charge density and dielectric strength. Superior oxide characteristics were obtained by adding hydrogen to the discharge gas particularly in the area of oxide breakdown statistics. Values of the intrinsic breakdown field in the range from 8 MV/ cm to 14 MV/cm were recorded in this case.