JPH05133734A - Thickness sensor - Google Patents

Abstract

PURPOSE:To provide a sensor for measuring the thickness, with which the measurement can be done easily and in which measuring errors due to electrons, or ions reaching the base board are not likely to be produced at the time of measuring the thickness of an attachment layer in the case where electrical signals are used in a heating/cooling means or a temp. sensing means. CONSTITUTION:A means 3 to heat or cool a specified position on a base board and a means 4 to sense specific temp. on the base board are furnished on the base board 2 made of a poor conductive material in connection thermally with a heat sink 1. A grounded conductor 5 is also provided which surrounds at least part of the base board 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to measurement of film thickness such as deposits and deposits to be vapor-deposited in vacuum vapor deposition equipment, plasma CVD equipment and sputtering equipment, and plating thickness during Au plating.

[0002]

2. Description of the Related Art As a conventional technique, a crystal type film thickness detector has been used for measuring the film thickness of an adhered / deposited material deposited in a vacuum deposition apparatus, a plasma CVD apparatus, a sputtering apparatus or the like. The crystal type film thickness detector utilizes the phenomenon that the resonance frequency of the crystal unit changes according to the film thickness of the deposited film.
It is characterized by high detection accuracy and fast response speed. In addition, recently, electron impact excitation spectroscopy using excitation light by electron impact of evaporated metal has been used.
In electron-impact excitation spectroscopy, when thermoelectrons collide with the vapor stream of a vapor deposition substance, the vaporized substance is excited, and light with a wavelength spectrum peculiar to the substance is emitted. It uses a phenomenon that is proportional to speed,
In particular, it has a feature that binary simultaneous vapor deposition can be detected by providing an optical filter in the detector. As another conventional technique, an amorphous semiconductor thin film having a large Seebeck coefficient has been reported (Japanese Patent Publication No. 2-27826) (Japanese Patent Laid-Open No. 186900).

[0003]

However, the crystal resonance frequency method requires a stable frequency oscillator and a frequency counter, and since the crystal resonator cannot be downsized, the film thickness detector can be downsized. -There was a problem that integration was difficult, it was easily affected by high frequency noise, and measurement was complicated. In addition, electron impact excitation spectroscopy requires a highly sensitive light receiver and thermionic emitter, and is extremely expensive, and the detection unit is composed of a light emitter and a light receiver, making it difficult to miniaturize and integrate. However, there is also a problem that the measurement method is complicated. And regarding the amorphous semiconductor thin film having a large Seebeck coefficient,
No specific disclosure of a thickness sensor utilizing changes in thermal resistance has been obtained. Therefore, it is a first object of the present invention to solve these conventional problems that are easily affected by high frequency noise, difficult to miniaturize, expensive, and complicated in measurement.

Further, in order to solve the problems of the present invention, in the thickness sensor and the method for measuring the thickness of the adhesion layer (Japanese Patent Application No. 2-248136) filed by the same applicant, heating or cooling means, Alternatively, when an electric signal is used for the temperature detecting means, when electrons or ions reach the substrate of the heat-defective conductor when measuring the thickness of the adhesion layer, a means for heating or cooling by the influence of these electrons or ions,
Alternatively, it becomes difficult to detect the electric signal used for the temperature detecting means, and as a result, the accuracy of the film thickness measurement may not be maintained. For example, in the case of heating an object to be vapor-deposited by an electron gun, electrons from the electron gun or ions generated thereby reach the substrate, and it is difficult to maintain the accuracy of film thickness measurement due to the influence of these electrons or ions. Was becoming. Further, even when a large amount of ions are generated during thin film deposition as seen in plasma CVD, ECRCVD, photo CVD, etc., these ions reach the substrate, and similarly it becomes difficult to measure the film thickness. Therefore, another object of the present invention is to solve the difficulty of measuring the thickness of the adhesion layer due to the influence of electrons or ions generated during the measurement of the thickness of the adhesion layer.

[0005]

In order to solve the above-mentioned problems, the present invention provides a substrate 2 of a heat-defective conductor thermally connected to a heat sink 1 (hereinafter sometimes referred to simply as substrate 2).
A means 3 for heating or cooling, a temperature detecting means 4 for detecting the temperature at a desired position on the substrate 2, and an electrically grounded conductor 5 surrounding at least a part of the substrate 2.
Composed of and. As described above, according to the present invention, the substrate 2 of the heat-defective conductor thermally connected to the heat sink 1 is heated or cooled, and the temperature change depending on the thickness of the deposit adhered to the substrate 2 is detected. Is used to measure the thickness of the adhesion layer. The substrate 2 is also surrounded by an electrically grounded conductor 5.

[0006]

The thickness sensor of the present invention thus constructed has the following effects. When a substance adheres to the substrate 2 of this thickness sensor by vapor deposition or the like, the thermal resistance of the substrate 2 decreases. At this time, when the predetermined position of the substrate 2 is heated, the temperature of the desired position decreases, and conversely, when the substrate 2 is cooled, the temperature of the desired position increases. This decrease or increase in temperature corresponds to the film thickness of the adhesion layer, and the film thickness of the adhesion layer can be measured by detecting the decrease or increase in temperature. In the thickness sensor of the present invention, at least a part of the substrate 2 is surrounded by the electrically grounded conductor 5, so that electrons or ions traveling toward the substrate 2 are prevented from reaching the substrate 2. It Then, these electrons and ions reach the conductor 5, and the electrons or ions reaching the conductor 5 pass through the substance of the conductor 5 and are grounded. Therefore, the influence of these electrons or ions on the means 3 for heating or cooling the thickness sensor or the temperature detecting means 4 is prevented. As a result, a thickness sensor that is not affected by electrical noise can be obtained, and accurate thickness measurement becomes possible.

[0007]

EXAMPLE A thickness sensor according to the present invention is a heat sink 1.
On the substrate 2 of the heat-defective conductor that is thermally connected to the substrate 2, the means 3 for heating or cooling a predetermined position of the substrate 2, and the means 3 for heating or cooling the substrate 2. Means 4 for measuring the temperature at the desired position,
It is composed of an electrically grounded conductor 5 which surrounds at least part of the substrate 2. FIG. 1 is a view showing an embodiment of a thickness sensor according to the present invention, in which a thin film heater 31 and a temperature detecting means 4 as a heating or cooling means 3 are provided on a substrate 2 which is thermally connected to a heat sink 1. And a thin film thermocouple 41, which further surrounds a portion of the substrate 2 and is electrically grounded.
It consisted of 2, 53.

In the embodiment shown in FIG. 1, electrons or ions traveling to the substrate 2 are prevented from reaching the substrate 2 and reach the conductors 51, 52 and 53. Then, it passes through the conductors 51, 52, 53 and is grounded. As a result, even in a measurement environment in which electrons or ions are generated, a thickness sensor that is not affected by these electrons or ions can be obtained, and the thickness of the adhesion layer can be accurately measured. Further, these conductors 51, 52 and 53 naturally prevent the electromagnetic waves from entering the substrate 2, so that the thickness measurement which is not affected by the electromagnetic waves can be performed at the same time. Further, in the embodiment shown in FIG. 1, since the conductor 52 covers the substrate 2 of the heat-defective conductor, the thin film heater 31 for heating or the thin film thermocouple 41 for temperature detection is provided with a gold wire ( (Not shown) or the like, these conductors 52 can protect these gold wires. In the thickness measurement in vacuum, the thin film heater 31 or the thin film thermoelectric 4
There is a problem that the temperature detection signal changes due to the pressure change in the vicinity of 1. However, in the embodiment shown in FIG. 1, the pressure in the vicinity of the thin film heater 31 or the thin film thermocouple 41 is kept constant by the conductor 52. Therefore, accurate thickness measurement in vacuum is possible.

Here, each material will be described. The conductor 5 is required to have a thin film thickness, be formed uniformly, and be capable of suppressing the reduction of the substrate due to the adhesion of the conductor to a small extent. That is, it is preferable to have high electrical conductivity for grounding, and to have low thermal resistance for measuring the thickness of the adhesion layer so that it does not affect the measurement. Is essential.
Therefore, as the material of the conductor 5, aluminum, gold,
Platinum or the like is used. The heat sink 1 may be a block-shaped object having a large heat capacity, or may be connected to a conductive wire that guides heat well to the outside. As the material of the substrate 2, it is preferable that the thermal resistance greatly changes with a slight film thickness of the adhesive layer, so that a material having a small thermal conductivity of the adhesive layer is suitable. Therefore, as the material of the substrate 2, an organic film such as glass, ceramic, crystal, quartz, acrylic, epoxy, or polymide is used. The means 3 for heating or cooling a predetermined position of the substrate 2 includes resistance heating by electricity, absorption heating by a light absorbing film by light, cooling by a Peltier effect, or the like. In the embodiment shown in FIG. 1, a thin film heater 3 is used as a means for heating a predetermined position of the substrate 2.
1 is used. The means 4 for measuring the temperature at a desired position on the substrate 2 may be a thermocouple, a radiation thermometer, or the like. In FIG. 1, the temperature is measured using a thin film thermocouple 41 and an ohmic electrode 6 (hereinafter, simply referred to as an electrode) for measuring a potential difference between the thin film thermocouple 41 and the thin film thermocouple 41.

A thickness sensor according to the present invention is now shown in FIG.
An example of the manufacturing method of the embodiment shown in will be briefly described. As the substrate 2 of the heat-defective conductor, an organic film such as glass, ceramic, crystal, quartz, acrylic, epoxy, or polymide is used as described above. This board 2
After being thoroughly washed with an organic solvent or the like, it is dried in a clean environment. Next, the thin film thermocouple 41 is formed. Thin film thermocouple 4
1 preferably has a large Seebeck coefficient, and an amorphous semiconductor thin film such as amorphous silicon or amorphous germanium is used. These amorphous semiconductors use gases such as silane, germane, and hydrogen,
It is deposited by the plasma CVD method. At this time, a doping gas such as phosphine or arsine is supplied to the n-type semiconductor, and a doping gas such as cyborane is supplied to the p-type semiconductor to change the conductivity or the like. An unnecessary portion of the deposited amorphous semiconductor is removed by using a photoetching technique, and a predetermined thin film thermocouple 4 is formed.
1 is formed. The thin film thermocouple 41 may be composed of an amorphous thin film having a large Seebeck coefficient and a small metal thin film. Then, the thin film heater 31 is formed. As the thin film resistor, a metal thin film such as nichrome or tantalum is used. These thin films are deposited by sputtering or vacuum evaporation. Similarly, this thin film is formed by removing unnecessary portions to form a thin film heater 31 having a desired shape.
Further, a metal thin film for electrodes such as gold is deposited and unnecessary portions are similarly removed to form electrodes for the thin film thermocouple 41 and the thin film heater 31. Note that a silicon dioxide thin film, a silicon nitride thin film, or the like may be provided as the surface protective film. Then, the conductors 51, 52, 53 are aluminum, gold,
A substance such as platinum is deposited by a sputtering method or a vacuum evaporation method. In addition, unnecessary portions are removed as needed.

FIG. 2 is a diagram showing another embodiment according to the present invention. In the embodiment shown in FIG. 2, the heat sink 1
Are in thermal contact with the same surface as the surface on which the thin film heater 31 and the thin film thermocouple 41 are formed. In this case, since the vapor deposition material can reach the thickness monitor portion without passing through the vicinity of the heat sink 1, the accurate thickness can be measured even when the vapor deposition material cannot be vapor deposited vertically to the thickness monitor portion such as oblique vapor deposition. There is a feature called. Further, since the heat sink 1 is also surrounded by the conductors 51 and 52 which are electrically grounded, there is also a feature that the conductors 51 and 52 can be formed after all the thickness sensors are manufactured.
The heat sink 1 may be a conductor.

FIG. 3 is a diagram showing another embodiment according to the present invention. In the embodiment shown in FIG. 3, the thin film heater 3
1. Conductors 51, 52, 53 electrically grounded via the insulating film 7 are formed on the thin film thermocouple 41. Therefore, the conductor 51,
It is possible to consistently perform the steps up to 52, 53 formation,
As a result, there is a feature that low cost, miniaturization, and integration are possible. Further, in the embodiment shown in FIG. 3, when the substrate 2 is thin, even if the conductor is not formed on the side surface of the substrate,
Since the ion or electron thickness sensor is less affected, the conductor on this side can be removed.

[0013]

The thickness sensor according to the present invention comprises a substrate 2 of a heat-defective conductor which is thermally connected to a heat sink 1, and means 3 for heating or cooling a predetermined position of the substrate 2.
A temperature detecting means 4 for measuring the temperature of a desired position on the substrate 2 heated or cooled by the heating or cooling means 3 and an electrically grounded surrounding at least a part of the substrate 2. It is composed of a conductor 5. With such a configuration, the present invention can achieve the following effects. First, the measurement is not complicated and is not affected by high frequency noise. In addition, miniaturization and integration can be easily achieved by using semiconductor thin film technology and the like, and the manufacturing cost is very low. Further, since the thickness sensor of the present invention surrounds the substrate 2 by using the conductor 5 which is electrically grounded, it prevents electrons or ions traveling toward the substrate 2 from reaching the substrate 2. Further, the conductor 5 can be passed to be grounded. By surrounding at least a part of the substrate 2 with the electrically grounded conductor 5, the influence of electrical noise on the thickness sensor can be prevented. Therefore, due to the influence of these electrons or ions,
The conventional problem that it becomes difficult to detect the electric signal used for the heating or cooling means 3 and the temperature detecting means 4 and as a result, the thickness measurement becomes difficult is solved, and accurate thickness measurement is achieved. Will be realized.

[0014]

[Brief description of drawings]

FIG. 1 is a view showing an embodiment of a thickness sensor according to the present invention,

FIG. 2 is a view showing another embodiment of the thickness sensor according to the present invention.

FIG. 3 is a view showing another embodiment of the thickness sensor according to the present invention.

[Brief explanation of sign]

 1 heat sink. 2 A substrate of poor heat conductor. 3 Means of heating or cooling. 4 Temperature detection means. 5 Conductor. 6 Ohmic electrodes. 7 Insulating film. 31 Thin film heater. 41 Thin film thermocouple. 51 A conductor that is electrically grounded. 52 A conductor that is electrically grounded. 53 A conductor that is electrically grounded.

Claims (1)

[Claims] 1. A substrate (2) of a heat-defective conductor which is thermally connected to a heat sink (1), means (3) for heating or cooling a predetermined position of the substrate, and means for heating or cooling the same. Temperature detection means (4) for detecting the temperature of a desired position on the substrate which has been heated or cooled, and at least a part of the substrate is surrounded by a conductor (5) which is electrically grounded. An adhesive layer thickness sensor characterized in that.