Abstract:
A method and composition for removing silicon-containing sacrificial layers from Micro Electro Mechanical System (MEMS) and other semiconductor substrates having such sacrificial layers is described. The etching compositions include a supercritical fluid (SCF), an etchant species, a co-solvent, and optionally a surfactant. Such etching compositions overcome the intrinsic deficiency of SCFs as cleaning reagents, viz., the non-polar character of SCFs and their associated inability to solubilize polar species that must be removed from the semiconductor substrate. The resultant etched substrates experience lower incidents of stiction relative to substrates etched using conventional wet etching techniques.
Abstract:
An etching process is provided. The etching process allows etching and removing with a sufficient rate, from a fine etching opening, a sacrificing layer and thereby can form a structure that has a large hollow portion or a complicatedly constituted space portion and furthermore a structure high in the aspect ratio with excellent shape accuracy and without deteriorating a surface state. In the etching process, a work is exposed to a processing fluid that contains an etching reaction species and the processing fluid is maintained in a state where it is flowed relative to the work. In this state, on a surface of the work, illumination light is intermittently illuminated to heat the work intermittently. Thereby, the processing fluid in the neighborhood of the work is intermittently heated and thereby expanded and contracted to etch. As the processing fluid, a substance that contains an etching reaction species and is in a super critical state can be preferably used.
Abstract:
A surface treatment method of treating a surface having structural bodies formed thereon using a supercritical fluid (4) is characterized in adding a co-solvent or a reactant (5) such as ammonium hydroxide, alkanolamine, amine fluoride, hydrofluoric acid and so forth to the supercritical fluid (4). The supercritical fluid (4) may also be added with a surfactant (6) together with the co-solvent or the reactant (5). It is allowable to use a polar solvent as the surfactant (6). This makes it possible to provide a surface treatment method capable of thoroughly removing the residue only by a treatment using the supercritical fluid.
Abstract:
A process and apparatus for the processing of a precision surface. The process and apparatus includes contacting of a precision surface in a process chamber with liquid or supercritical carbon dioxide in which sonic waves are generated.
Abstract:
A method of coating one or more surfaces of a micromechanical device. The coating is applied as a material dissolved in CO2. The CO2 is used a carrier solvent, with the coating being applied as a spray or in liquid form, to form a film on the surface. The CO2 may be used in supercritical form to dissolve the material.
Abstract:
An inventive method for the manufacture of a thin film actuated mirror array comprises the steps of: preparing an active matrix including a substrate, an array of switching devices and an array of connecting terminals; forming a first sacrificial layer including an array of empty cavities; forming an array of actuating structures, each of the actuating structures including an elastic member, a lower electrode, an electrodisplacive member, an upper electrode and a via contact; forming a second sacrificial layer including an array of empty slots; forming an array of mirrors; removing the first and the second sacrificial layer to thereby form the thin film actuated mirror array. The use of a poly-Si as the material for the first and the second sacrificial layers will ensure an easy flattening thereof and an easy removal thereof, resulting an increased otpical efficiency in the thin film actuated mirror thus formed.
Abstract:
A structural body comprising a substrate and a structural layer formed on the substrate through an air gap in which the structural layer functions as a micro movable element is produced by a process comprising a film-deposition step of successively forming a sacrificial layer made of a silicon oxide film and the structural layer on the substrate, an air gap-forming step of removing the sacrificial layer by etching with a treating fluid to form the air gap between the substrate and the structural layer, and a cleaning step. By using a supercritical carbon dioxide fluid containing a fluorine compound, a water-soluble organic solvent and water as the treating fluid, the sacrificial layer is removed in a short period of time with a small amount of the treating fluid without any damage to the structural body.
Abstract:
A structural body comprising a substrate and a structural layer formed on the substrate through an air gap in which the structural layer functions as a micro movable element is produced by a process comprising a film-deposition step of successively forming a sacrificial layer made of a silicon oxide film and the structural layer on the substrate, an air gap-forming step of removing the sacrificial layer by etching with a treating fluid to form the air gap between the substrate and the structural layer, and a cleaning step. By using a supercritical carbon dioxide fluid containing a fluorine compound, a water-soluble organic solvent and water as the treating fluid, the sacrificial layer is removed in a short period of time with a small amount of the treating fluid without any damage to the structural body.
Abstract:
A method of cleaning and treating a device, including those of the micromechanical (10) and semiconductor type. The surface of a device, such as the landing electrode (22) of a digital micromirror device (10), is first cleaned with a supercritical fluid (SCF) in a chamber (50) to remove soluble chemical compounds, and then maintained in the SCF chamber until and during the subsequent passivation step. Passivants including PFDA and PFPE are suitable for the present invention. By maintaining the device in the SCF chamber, and without exposing the device to, for instance, the ambient of a clean room, organic and inorganic contaminants cannot be deposited upon the cleaned surface prior to the passivation step. The present invention derives technical advantages by providing an improved passivated surface that is suited to extend the useful operation life of devices, including those of the micromechanical type, reducing stiction forces between contacting elements such as a mirror and its landing electrode. The present invention is also suitable for cleaning and passivating other surfaces including a surface of semiconductor wafers, and the surface of a hard disk memory drive.
Abstract:
A method (10) for drying an object having a polymeric film, wherein the object is submerged in a rinse liquid. The object is removed from the rinse liquid (20) and the object is placed in a solvent bath (20) before a sufficient amount of the rinse liquid can evaporate from the object (20). The density of a solvent in the solvent bath depends on a direction of orientation of the polymeric film with respect to a force. The object is removed from the solvent bath (30). A drying process is performed (40).