Oxidation of silicon surfaces by CO2 lasers
TL;DR: In this paper, the use of a focussed CO2 laser beam and a controlled oxygen atmosphere to induce localized oxidation on the surface of a silicon wafer was reported for the first time.
Abstract: We report for the first time, the use of a focussed CO2 laser beam and a controlled oxygen atmosphere to induce localized oxidation on the surface of a silicon wafer. These thin oxide films have been compared by infrared spectrometry with thin furnace‐grown layers. We conclude that the laser‐grown oxides are compositionally similar to conventional layers, and can be described by the formula SiO2. In contrast the half‐width of the Si‐O stretching vibration at 1070 cm−1 was found to be consistently less than for furnace‐grown oxides. By fabricating simple Al‐SiO2‐Si‐Al diodes, the dielectric properties of the films have been studied.
Citations
More filters
Patent•
16 Aug 2004
TL;DR: In this paper, the TFTs are fabricated using an active layer crystallized by making use of nickel, and the gate electrodes are comprising tantalum, and a heat treatment is performed to getter nickel element in the active layer and to drive it into the source/drain regions.
Abstract: There are disclosed TFTs that have excellent characteristics and can be fabricated with a high yield. The TFTs are fabricated, using an active layer crystallized by making use of nickel. Gate electrodes are comprising tantalum. Phosphorus is introduced into source/drain regions. Then, a heat treatment is performed to getter nickel element in the active layer and to drive it into the source/drain regions. At the same time, the source/drain regions can be annealed out. The gate electrodes of tantalum can withstand this heat treatment.
174 citations
Patent•
30 Dec 2005
TL;DR: In this article, an external force is applied to a support originally having curvature and elasticity, and the support is bonded to a peeled layer formed over a substrate, and then when the substrate is peeled, the support returns into the original shape by the restoring force and the peeled layer as well is curved along the shape of the support.
Abstract: The object of the invention is to provide a method for fabricating a semiconductor device having a peeled layer bonded to a base material with curvature. Particularly, the object is to provide a method for fabricating a display with curvature, more specifically, a light emitting device having an OLED bonded to a base material with curvature. An external force is applied to a support originally having curvature and elasticity, and the support is bonded to a peeled layer formed over a substrate. Then, when the substrate is peeled, the support returns into the original shape by the restoring force, and the peeled layer as well is curved along the shape of the support. Finally, a transfer object originally having curvature is bonded to the peeled layer, and then a device with a desired curvature is completed.
122 citations
TL;DR: In this paper, a novel processing technique is described in which coupling of the CO2 laser radiation to the Si lattice is significantly enhanced by the simultaneous absorption of radiation from an argon laser.
Abstract: The absorption of 9–11 μm radiation by thin wafers of lightly doped, n‐type Si has been measured at several lattice temperatures from 300 to 800 K. The temperature dependence of the absorption coefficient at λ=10.6 μm is extracted from the data and compared with previous measurements and also with recent theoretical models. A novel processing technique is described in which coupling of the CO2 laser radiation to the Si lattice is significantly enhanced by the simultaneous absorption of radiation from an argon laser.
60 citations
TL;DR: The photochemical vapor deposition (photo-CVD) has attracted the greatest attention among various photo-induced methods as discussed by the authors, which is often used to photolyze source gases either in the gas phase or on substrate surfaces.
56 citations
Patent•
25 Jun 1996
TL;DR: In this article, a catalytic element is applied in contact with the surface of the amorphous silicon film and the film is heated at 450 to 650°C to create crystal nuclei.
Abstract: In thin film transistors (TFTs) having an active layer of crystalline silicon adapted for mass production, a catalytic element is introduced into doped regions of an amorphous silicon film by ion implantation or other means. This film is crystallized at a temperature below the strain point of the glass substrate. Further, a gate insulating film and a gate electrode are formed. Impurities are introduced by a self-aligning process. Then, the laminate is annealed below the strain point of the substrate to activate the dopant impurities. On the other hand, Neckel or other element is also used as a catalytic element for promoting crystallization of an amorphous silicon film. First, this catalytic element is applied in contact with the surface of the amorphous silicon film. The film is heated at 450 to 650° C. to create crystal nuclei. The film is further heated at a higher temperature to grow the crystal grains. In this way, a crystalline silicon film having improved crystallinity is formed.
53 citations
References
More filters
TL;DR: In this paper, the intrinsic breakdown mechanism in films of thermal SiO2 in the thickness range 30-300 A was studied and it was determined that high-field and high electron injection current conditions existing in the films just prior to breakdown result in the generation of a very high density of defects which behave electrically as stable electron traps.
Abstract: A novel technique is described which was used to study the intrinsic breakdown mechanism in films of thermal SiO2 in the thickness range 30–300 A. It was determined that high‐field and high electron injection current conditions existing in the films just prior to breakdown result in the generation of a very high density of defects which behave electrically as stable electron traps. These traps are most likely generated close to the injecting electrode. The internal field in the oxide due to trapped electrons can approach 3×107 V/cm which appears to be the maximum field strength which Si‐O bonding can withstand. At all temperatures between 77 and 393 °K, the breakdown mechanism is intimately related to the rate of generation of the electron traps. No evidence was found to support the impact ionization breakdown model. The technique is also described as a tool for yield measurements, with important implications for long‐term reliability of MOS IC’s.
420 citations
IBM1
TL;DR: In this paper, it has been established that by the use of infrared absorption spectroscopy, preferential etching procedures, precise optical measurements of thickness, density, and refractive indices, and carefully chosen environmental tests, differences in the oxide films can be determined.
Abstract: Techniques for physical and chemical evaluation of silicon oxide films formed by a wide variety of techniques have been developed It has been established that by the use of infrared absorption spectroscopy, preferential etching procedures, precise optical measurements of thickness, density, and refractive indices, and carefully chosen environmental tests, differences in the oxide films can be determined Techniques of oxidation studied were: thermal (oxygen and steam), evaporated, pyrolytic, lead catalyzed, sputtered and anodic In many cases, improvement of oxide film properties can be achieved by simple thermal treatment of the original films
341 citations
TL;DR: In this article, a series of silicon dioxide (SiO2) films grown on silicon wafers from a HCl and O2 gas mixture at 850°C, have been studied for film thicknesses down to 28 A. The validity of Lambert Bouguer's Law for such thin films has been confirmed, and the apparent absorption coefficient calculated for the absorption at 1065 cm−1 is in good agreement with previously published data for thicker, vapordeposited, and thermally grown films.
Abstract: Infrared transmission spectra of a series of silicon dioxide (SiO2) films grown on silicon wafers from a HCl and O2 gas mixture at 850 °C, have been studied for film thicknesses down to 28 A. The validity of Lambert‐Bouguer’s Law for such thin films has been confirmed, and the apparent absorption coefficient calculated for the absorption at 1065 cm−1 is in good agreement with previously published data for thicker, vapor‐deposited, and thermally grown films. A continuous shift of the absorption near 1065 cm−1 has been found, moving from an asymptotic limit maximum of ∼1070 cm−1 for thick films towards smaller wave numbers for thinner films. Various possibilities for the origin of this shift are discussed.
164 citations