JP2007115939A - Dry etching device, method, and crystal oscillator with film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dry etching device which is capable of carrying out a dry etching work in a short time, and furthermore satisfying strict requirements as to tolerance sufficiently. <P>SOLUTION: A dry etching means 1 is prepared. A material 5 to be etched is arranged so as to be etched by the dry etching means 1. A crystal oscillator 2 is arranged so as to be dry-etched by the dry etching means 1 under the same condition as the etched material 5. A film thickness control device 3 is connected to the crystal oscillator 2. The material 5 to be etched and the crystal oscillator 2 are etched by the dry etching means 1. The frequency of the crystal oscillator 2 is monitored by the film thickness control device 3 in an etching operation, and the weight of matter removed from the crystal oscillator 2 is obtained on the basis of a frequency change. The weight of the removed matter is converted to a thickness subtracted from the etched material 5, and the etching operation carried out by the dry etching means 1 is stopped when the converted thickness reaches to a prescribed value. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The present invention relates to a dry etching apparatus and method, and a film-coated crystal resonator used in these apparatuses.
The present invention is particularly useful for a technique for forming a groove in a slider of a thin film magnetic head, but is not limited thereto.

  A thin film magnetic head of a hard disk drive is required to maintain a 10 nanometer level gap with the disk. Therefore, a complicatedly shaped groove is formed on the disk-facing surface side of the slider provided in the thin film magnetic head, and the aerodynamic characteristics generated there are utilized. The groove of the slider is formed by dry etching means such as an ion milling apparatus under a vacuum environment.

  With the demand for a smaller gap between the head and the disk, the tolerance range for the groove depth of the slider has become very strict. Conventionally, the etching amount of an ion milling apparatus that has been widely used for groove formation is almost the product of ion energy (voltage), ion current density (current), ion incident angle etching coefficient (physical characteristics), and etching time. Determined. Therefore, in forming the slider groove, parameters other than the time are fixed, and the etching amount is controlled by the time.

  However, the actual etching amount involves an error that varies each time due to environmental factors. Further, if the etching is performed to a depth greater than or equal to a predetermined depth, the product will be completely lost, and excessive etching is not allowed.

  Therefore, the conventional method stops the etching action before reaching a predetermined etching amount, breaks the vacuum environment, removes the slider, and measures the etched depth with a stylus type surface roughness meter or the like. After that, a vacuum environment was formed again and the rest was etched.

  This method has been required to be improved because it takes about half of the time required for the originally unnecessary steps of evacuation for forming a vacuum environment again and measuring the etching amount during the operation.

  It is an object of the present invention to enable a dry etching operation in a short time by omitting the above-described originally unnecessary steps, and to sufficiently meet strict requirements regarding allowable errors.

In order to solve the above problems, according to the present invention,
Dry etching means for etching the material to be etched;
A crystal resonator disposed so as to be etched under the same conditions as the material to be etched;
The film thickness controller connected to the crystal unit is used to determine the thickness reduced from the material to be etched by monitoring the frequency of the crystal unit, and the reduced thickness has reached a predetermined value. Sometimes a film thickness control device for stopping the etching action by the dry etching means,
A dry etching apparatus is provided.

The crystal resonator can be a film-coated crystal resonator.
The film thickness control device has a function of stopping the etching action by the dry etching means in response to the passage of time until the predetermined thickness is reduced based on the thickness reduced from the material to be etched per unit time. Can be.

According to the invention,
Prepare dry etching means,
The material to be etched is arranged to be etched by the dry etching means,
A crystal resonator is arranged so as to be etched by the dry etching means under the same conditions as the material to be etched,
Connect the film thickness controller to the crystal unit,
Etching the material to be etched and the crystal resonator by the dry etching means,
During the etching operation, the film thickness control device monitors the vibration frequency of the crystal resonator, obtains the weight removed from the crystal resonator based on the change in the vibration frequency, and calculates the removed weight to the object. Converted to a thickness reduced from the etching material, when the converted value reaches a predetermined value, the etching action by the dry etching means is stopped,
A dry etching method is also provided.

Also in this method, the crystal resonator can be a crystal resonator with a film.
Further, based on the thickness reduced from the material to be etched per unit time, the etching action by the dry etching means can be stopped in response to the passage of time until the predetermined thickness is reduced.

According to the invention,
A crystal resonator with a film used together with a dry etching means and a film thickness control device,
A crystal mother body and a film body formed on the crystal mother body,
Connected to the film thickness controller, the film body is etched by the dry etching means under the same conditions as the material to be etched, and the weight removed by monitoring the change in the frequency by the film thickness controller is obtained. The removed weight is converted to a thickness reduced from the material to be etched.
A filmed quartz crystal is also provided.

  The film body can be made of the same material as the material to be etched.

  According to the present invention, it is possible to proceed with the etching work based on the result of simultaneous simulation of the etching amount in the same environment where the material to be etched is actually etched. It can be carried out.

  Also, since it is not necessary to break the vacuum environment during the etching operation and measure the etching amount, it is possible to omit the vacuum evacuation and measurement process for forming the vacuum environment again, so the time required for the etching operation is about half that of the conventional method. That's okay.

  FIG. 1 is a diagram schematically showing one embodiment of a dry etching apparatus according to the present invention. The dry etching apparatus includes dry etching means such as an ion beam milling apparatus 1, a crystal resonator 2, and a film thickness control device 3 connected to the crystal resonator 2.

The ion beam milling apparatus 1 can utilize a well-known thing, and has the housing 4 which can make a vacuum state inside.
A plurality of materials to be etched 5 to be etched by the ion beam milling apparatus 1 are arranged in the housing 4. The crystal unit 2 is arranged to be etched under the same conditions as the material to be etched 5. For example, the crystal unit 2 may be arranged in place of the material to be etched 5 in one place of a planetary stage where a plurality of materials to be etched 5 can be uniformly etched.

  The crystal resonator 2 can be a film-coated crystal resonator composed of a crystal matrix and a film body formed so as to be attached (bonded) to the vibration surface of the crystal carrier. The film body is formed to a thickness close to the limit at which the film thickness control device 3 can measure the frequency of the crystal resonator 2. The material of the film body is preferably the same as the material of the material to be etched 5. However, as long as the etching characteristics have a clear correlation with the material of the material to be etched 5, film bodies of other materials can be employed.

  Further, in the case where the material to be etched 5 and the crystal matrix have a clear correlation with respect to the etching characteristics, only the crystal matrix on which no film body is formed can be used as the crystal resonator 2.

  As the film thickness control device 3, a known device used for controlling the film thickness to be deposited in the vacuum deposition operation can be used. The film thickness control device 3 can know the weight removed from the crystal resonator 2 by monitoring the change in the frequency of the crystal resonator 2 etched by the ion beam milling device 1. Since the value simulates the weight value removed from the material to be etched 5 under the same conditions, the film thickness control device 3 is removed from the material to be etched 5 from the weight removed from the crystal resonator 2. Further, it can be obtained by converting the weight and the thickness reduced from the material 5 to be etched.

  The film thickness control device 3 also knows the thickness (subtraction rate) actually reduced from the material to be etched 5 per unit time until the predetermined thickness is reduced from the material to be etched 5 based on this subtraction rate. You can ask for time.

  The film thickness control device 3 can output a signal for stopping the etching action of the ion beam milling device 1 when the thickness reduced from the material to be etched 5 reaches a predetermined value. In this case, a signal for stopping the etching action of the ion beam milling apparatus 1 may be generated in response to the elapse of time until the predetermined thickness is reduced from the material to be etched 5.

  A dry etching method according to the present invention will be described. In the ion beam milling apparatus 1 which is a dry etching means, the material to be etched 5 and the crystal resonator 2 are arranged so as to be etched under the same conditions. The crystal unit 2 is connected to the film thickness controller 3. After the inside of the housing 4 is evacuated to form a vacuum environment, the ion beam milling apparatus 1 starts an etching operation. At the same time, the film thickness controller 3 starts monitoring the frequency of the crystal unit 2 and obtains the weight removed from the crystal unit 2 based on the change in the frequency. The film thickness control device 3 converts the value of the weight removed from the crystal resonator 2 into a thickness reduced from the material to be etched. The calculation formula for conversion differs depending on the correlation between the etching characteristics of the material to be etched 5 and the etching characteristics of the material of the crystal resonator 2 to be etched. When a film body made of the same material as the material to be etched 5 is formed on the vibration surface of the crystal resonator 2, a more accurate conversion will be performed.

  When the thickness (converted value) reduced from the material to be etched 5 reaches a predetermined value, the film thickness control device 3 issues a signal for causing the ion beam milling device 1 to stop the etching action. By monitoring, the thickness actually reduced from the material to be etched 5 per unit time, that is, the subtraction rate, and based on this, the time until the predetermined thickness of the material to be etched 5 is reduced, It may be considered that the thickness reduced from the material to be etched 5 has reached a predetermined value.

  In stopping the etching action of the ion beam milling apparatus 1, the operation of the ion beam milling apparatus 1 may be stopped, or the etching action rate is set to zero, that is, the etching amount per unit time is zero. It may be made to become.

  As the dry etching means, an apparatus other than the ion beam milling apparatus can be used.

It is the schematic which showed typically the dry etching apparatus by one embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Ion beam milling apparatus (dry etching means), 2 Crystal oscillator, 3 Film thickness control apparatus, 4 Housing, 5 Material to be etched.

Claims (8)

Dry etching means for etching the material to be etched;
A crystal resonator disposed so as to be etched under the same conditions as the material to be etched;
The film thickness controller connected to the crystal unit is used to determine the thickness reduced from the material to be etched by monitoring the frequency of the crystal unit, and the reduced thickness has reached a predetermined value. Sometimes a film thickness control device for stopping the etching action by the dry etching means,
A dry etching apparatus comprising:   The dry etching apparatus according to claim 1, wherein the crystal resonator is a crystal resonator with a film.   The film thickness control device has a function of stopping the etching action by the dry etching means in response to the passage of time until the predetermined thickness is reduced based on the thickness reduced from the material to be etched per unit time. The dry etching apparatus according to claim 1 or 2. Prepare dry etching means,
The material to be etched is arranged to be etched by the dry etching means,
A crystal resonator is arranged so as to be etched by the dry etching means under the same conditions as the material to be etched,
Connect the film thickness controller to the crystal unit,
Etching the material to be etched and the crystal resonator by the dry etching means,
During the etching operation, the film thickness control device monitors the vibration frequency of the crystal resonator, obtains the weight removed from the crystal resonator based on the change in the vibration frequency, and calculates the removed weight to the object. Converted to a thickness reduced from the etching material, when the converted value reaches a predetermined value, the etching action by the dry etching means is stopped,
Dry etching method.   The dry etching method according to claim 4, wherein the crystal resonator is a crystal resonator with a film.   The dry action according to claim 4 or 5, wherein the etching action by the dry etching means is stopped in response to elapse of time until the predetermined thickness is reduced based on the thickness reduced from the material to be etched per unit time. Etching method. A crystal resonator with a film used together with a dry etching means and a film thickness control device,
A crystal mother body and a film body formed on the crystal mother body,
Connected to the film thickness controller, the film body is etched by the dry etching means under the same conditions as the material to be etched, and the weight removed by monitoring the change in the frequency by the film thickness controller is obtained. The removed weight is converted to a thickness reduced from the material to be etched.
Crystal resonator with film. The filmed crystal resonator according to claim 5, wherein the film body is made of the same material as the material to be etched.

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