Liquid phase etching method and liquid phase etching apparatus
View Patent ↗A liquid phase etching method which comprises spraying a chemically reactive liquid, with a specific speed, to a solid article, an aggregate of solid articles or a gelatinous material to be treated; and a liquid etching apparatus having a mechanism for holding a processing object to be treated and a nozzle structure for spraying a chemically reactive liquid to the processing object to be treated which is held by the mechanism. The method and apparatus allow the significant improvement of the etching rate while maintaining the accuracy of etching.
1. A liquid phase etching method comprising the steps of:
spraying a chemical reactive liquid to a processing object at a specified speed, by using a nozzle mechanism; and
etching the processing object by the sprayed liquid,
wherein the spraying step is conducted in a vacuum atmosphere of higher degree of vacuum than 1E-3 Torr, thereby preventing occurrence of impulse waves surpassing the sonic speed at the time of injection of the liquid.
2. The liquid phase etching method of claim 1 , wherein the spraying step is the step of spraying the liquid to the processing object as liquid particles smaller than 0.2 μm.
3. The liquid phase etching method of claim 1 , wherein the spraying step includes the steps of:
applying an electric charge to particles of the liquid, and
applying an electric field or magnetic field to the charged liquid particles, and the liquid particles are impinged on the processing object surface by induced acceleration or induced deceleration.
4. The liquid phase etching method of claim 3 , wherein electrons are supplied on the surface of the processing object which is electrically insulated from a holding mechanism.
5. The liquid phase etching method of claim 1 further comprising the step of coating part of the processing object with a coating material before the spraying step, wherein the etching step is a step of etching only the uncoated portion of the processing object with the liquid.
6. The liquid phase etching method of claim 1 further comprising the following sequential steps before the spraying step:
forming a thin film of substance not reacting with the liquid on the surface of the processing object;
coating part of the thin film with a coating material; and
etching the thin film by using the coating material as a mask,
wherein the etching step is a step of etching the processing object by using the etched thin film as mask.
7. The liquid phase etching method of claim 1 , wherein the spraying step is a step of spraying a surface active agent on the surface of the processing object, simultaneously with the spraying of liquid, or before or after the spraying.
8. The liquid phase etching method of claim 1 , wherein the spraying step is a step of spraying the liquid intermittently by using the nozzle mechanism.
9. The liquid phase etching method of claim 8 , wherein the time interval of spraying the liquid intermittently at the spraying step is determined, depending on the etching speed of the processing object by the liquid, and on vaporization speed or elimination speed of the liquid containing the etched substance at the end of etching in the vacuum atmosphere.