JP2000022476A - Manufacturing device for crystal vibrator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely inspect call cells of a vibrator on a wafer in a short time. SOLUTION: A y-direction moving stage 1 adjusts a position of a crystal wafer 6 placed on a sample stage 5 in a y axis (forward backward) direction, an x-direction moving stage 3 adjusts a position in an x-axis (left right) direction, a z-direction moving stage 4 adjusts a position in a z-axis (upper lower) direction to adjust sequentially a frequency measurement probe 7 at each vibrating position and the admittance of the vibration section of a wafer placed between an opposed electrode provided on the sample stage 5 and the probe 7 is measured to obtain sequentially the vibration frequency of the each vibrating part. Furthermore, the device contains the constitution as well in which the probes are arranged, in multi-channels of line-shape or face-shape and the position between the probe and the wafer is adjusted biaxially or uniaxially to obtain the vibrating frequency.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for manufacturing a quartz oscillator, and more particularly to an apparatus for inspecting a resonance frequency when photolithography is applied to a manufacturing process of a high-frequency quartz oscillator.

[0002]

2. Description of the Related Art A photolithography (photolithography) technique used in semiconductor manufacturing is being applied to a manufacturing process of a quartz oscillator. This technology reduces the thickness of crystal units,
That is, it is used to cope with a higher frequency.

[0003] The vibration frequency of a crystal unit is inversely proportional to the thickness of the crystal unit. For example, in order to obtain a fundamental vibration of 100 MHz or more, the thickness of the crystal resonator is 20 μm or less. Due to such thinning, in the manufacturing process of the crystal unit, it is very important to control the thickness accuracy of the crystal unit substrate, and slight variations in thickness greatly affect the vibration frequency of the crystal unit. This is for determining the product yield.

[0004] It is extremely difficult to realize such a thin and high-precision quartz substrate by conventional machining, and photolithography technology capable of high-accuracy machining has begun to be applied.

[0005] Further, with the increase in the precision of processing techniques, it is necessary to strictly control the thickness precision, and therefore, it is desired to perform a complete inspection of the vibration frequency of the crystal resonator during the process.

[0006]

In the photolithography process, in the etching process for adjusting the thickness of the quartz substrate, very strict control is required as the frequency becomes higher. This is because a slight thickness error greatly affects the product yield. In order to greatly improve the yield, it is necessary to perform fine etching while measuring the oscillation frequency of the quartz oscillator during the process.

[0007] In photolithography, a quartz oscillator is handled in a wafer unit in most of the manufacturing process. Therefore, a frequency measurement is typically performed at a representative point to determine an etching amount of the entire wafer. According to this method, the yield can be managed if the product has a relatively low frequency as in the related art. However, with the increase in the frequency of the quartz oscillator, it has become impossible to improve the yield unless the process is strictly controlled by completely inspecting the frequencies of all the oscillators on the wafer.

An object of the present invention is to provide an apparatus for manufacturing a quartz oscillator which can reliably inspect all cells of the oscillator on a wafer in a short time.

[0009]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a method of adjusting the relative position between a quartz wafer and a probe by using a three-axis moving stage in front, rear, left, right, and vertical directions. By adjusting the position using a probe and a two-axis moving stage, and adjusting the position using a planar probe and a one-axis moving stage, the frequency of all vibrating parts on the wafer can be measured.
The feature is as follows.

(First invention) In a crystal resonator manufacturing apparatus in which a vibrating portion is formed on a quartz wafer vertically and horizontally by etching and a vibration frequency is adjusted by adjusting the thickness of each vibrating portion, the device is mounted on a sample stage. For each vibrating portion position of the quartz wafer, a driving device for sequentially adjusting the position of the vibration frequency measurement probe in three axial directions, and a counter electrode on the sample stage, and the driving device interposed between the counter electrode and the probe. An admittance measuring device for measuring an admittance of each of the vibrating parts whose position has been adjusted and obtaining a vibration frequency of each of the vibrating parts.

(Second invention) In a crystal resonator manufacturing apparatus in which vibrating portions are formed vertically and horizontally on a quartz wafer by etching and the vibration frequency is adjusted by adjusting the thickness of each vibrating portion, the quartz oscillator is mounted on a sample stage. For each vibrating portion position of the quartz wafer, a driving device that sequentially adjusts the relative position of the linear probe in which the vibration frequency measurement probe is arranged in multiple channels in a linear manner in the front-back or left-right direction and the vertical direction, The sample stage has a counter electrode, and the admittance of each of the horizontal or vertical vibrating portions adjusted in position between the counter electrode and each probe of the linear probe by the driving device is sequentially switched and measured. An admittance measuring device for obtaining a vibration frequency of the vibrating part.

(Third invention) In a manufacturing apparatus of a quartz oscillator in which vibrating portions are formed vertically and horizontally on a quartz wafer by etching and a vibration frequency is adjusted by adjusting the thickness of each vibrating portion, the oscillator is mounted on a sample stage. A driving device that adjusts the relative position of a planar probe in which a plurality of channels of vibration frequency measuring probes are arranged in a planar manner with respect to the positions of the vibrating portions of the crystal wafer in one axial direction in a vertical direction; Having an admittance measuring device for sequentially switching and measuring the admittance of each of the vibrating parts whose position has been adjusted between the counter electrode and each of the planar probes by the driving device, and obtaining a vibration frequency of each vibrating part; It is characterized by having.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION For each vibrating portion on a quartz wafer, there is a known admittance measuring method for measuring a vibration frequency. Quartz vibrates at a frequency inversely proportional to the thickness of the quartz substrate when an electric field is applied from the outside. Since this change also affects the electrical characteristics and electric resonance is observed, if the admittance of each vibrating part on the crystal wafer is measured using a vibration frequency measurement probe that is not in contact with the crystal oscillator,
The vibration (resonance) frequency of each vibration unit can be measured.

FIG. 8 shows the structure (a) of a crystal resonator wafer and a vibrating section, and a method (b) for measuring the resonance frequency of each vibrating section of the crystal resonator. The crystal resonator wafer is manufactured as a resonator chip by thinning the vibrating portion by pattern etching, and thereafter cutting the vibrating portion.

To measure the frequency of each vibrating part, a counter electrode is brought into contact with the vibrator part on one side of a thinned quartz crystal wafer, and a frequency measuring probe is placed at a position facing the counter electrode from the other side. An admittance measuring device measures a change in admittance due to a difference in thickness of the vibrating portion located between the probe and the counter electrode, and obtains a measured value of a vibration frequency of the vibrating portion according to the admittance.

The apparatus for inspecting the total number of vibration frequencies according to this embodiment automatically or semi-automatically measures the vibration frequencies of all vibrating parts on a quartz wafer by using the above principle.

The first to fifth embodiments described below are:
With a driving device that mechanically operates the relative position between the quartz wafer and the vibration frequency measurement probe, the frequency is measured while sequentially switching and moving the relative positions of all the vibrating parts and the probes on the quartz wafer, Although the structures of the drive stages are different from each other, the operation of making the probe approach (but not contact) the vibrating part of the quartz wafer is common. In the sixth and seventh embodiments, the vibration frequency measuring probe has multiple channels so that a plurality of cells can be measured almost simultaneously.

(First Embodiment) Configuration Using an xyz Stage When performing 100% measurement using a needle-shaped probe as in the measurement principle, a driving device having three or more axes of freedom is required. It is. In this embodiment, as shown in FIG. 1, a driving device that drives a stage on which a quartz wafer is mounted, and an admittance measuring device that sequentially measures the vibration frequency of a vibrating portion on the wafer whose position is adjusted by the driving device. Be composed.

In FIG. 1, the y-direction moving stage 1 is
The position in the y-axis (front-rear) direction can be adjusted at the lowermost part of the device housing 2. The position of the x-direction moving stage 3 in the x-axis (left / right) direction on the y-direction moving stage 1 can be adjusted. The position of the z-direction moving stage 4 in the z-axis (vertical) direction on the x-direction moving stage 3 can be adjusted.

The position adjustment of the x, y, and z-direction moving stages is driven in each direction on a guide rail by using a pulse motor or a linear motor as a driving source, and is realized by controlling the number of rotations of the motor or performing position feedback control.

A sample stage 5 having a counter electrode is provided on the z-direction moving stage 4, and a crystal wafer 6 is mounted on the sample stage 5 to move the crystal wafer 6 in the x, y, and z directions. The position is adjusted.

A needle-like frequency measurement probe 7 is attached to the arm 2A pulled out of the apparatus housing 2 above the quartz wafer 6, and the tip of the probe 7 is attached to the quartz wafer 6.
Is adjusted by the x, y, z direction moving stage so as to be close to the vibrating part. The probe 7 and the counter electrode of the sample stage 5 are connected to an admittance measurement device (not shown) built in or external to the device housing 2.

Therefore, the frequency of each vibrating portion of the quartz wafer 6 on the sample stage 5 is measured by using a direction moving stage having three degrees of freedom of x, y and z so that the tip of the probe 7 is positioned at one vibrating portion. The frequency is measured by adjusting the position of the moving stage, and then the frequency of all vibrating parts can be measured by adjusting and measuring the position of the tip of the probe 7 at each vibrating part position by adjusting the position of the x, y direction moving stage. .

(Second Embodiment) z-drive probe and x-
Configuration using y-stage The present embodiment differs from the first embodiment in that, as shown in FIG. 2, a z-direction moving stage 4 is provided on a housing arm 2A, and a probe attached to this z-direction moving stage 4 7
Is driven in the z-axis direction.

Although the quartz cell surface does not contact the probe,
It is necessary to perform delicate position control in a very close proximity. In this embodiment, by independently driving a lightweight probe, controllability in the z-axis direction is excellent.

(Third Embodiment) Configuration Using a yz Drive Probe and an x Stage The present embodiment is different from the first or second embodiment in that:
As shown in FIG. 3, the position of the sample stage 5 is adjusted only in the x-axis direction by the x-direction moving stage 3, and the probe 7 is moved by the y-direction moving stage 1 provided in the housing 2 and the z-direction moving stage 4 supported by the same. The position is adjusted in two directions of y and z.

According to the present embodiment, when a large number of crystal wafers are measured continuously, continuous frequency measurement can be performed by feeding each wafer in the x-axis direction.

(Fourth Embodiment) Configuration Using xyz Drive Probe In this embodiment, as shown in FIG. 4, the x, y, and z direction moving stages 1, 3, and 4 are arranged on the housing 2 side. The quartz wafer 6 is fixed on the sample stage 5, and the probe 7 is
The frequency is measured successively while moving in the y and z axis directions.

According to the present embodiment, the arbitrariness of the position where the quartz wafer 6 is set is widened, and the present invention can be applied not only to the rectangular coordinate system but also to the cylindrical coordinate system.

(Fifth Embodiment) Configuration Using a Robot with Four or More Axes In this embodiment, as shown in FIG. 5, a multi-axis robot 8 having four or more axes of freedom is provided in a housing 2, and The position of the probe 7 is adjusted at the tip portion, and the frequency measurement of each vibrating portion of the wafer 6 is sequentially performed.

According to the present embodiment, the use of the robot 8 having a large number of off-the-shelf products on the market makes it possible to reduce the manufacturing cost as compared with the configurations of the above embodiments.

(Sixth Embodiment) Configuration Using Linear Probes In the present embodiment, a plurality of probes are used as shown in FIG. 6A to show the configuration and FIG. The probe is a linear probe 9 in which multiple channels are arranged in a line, and the degrees of freedom of the driving system are two axes by the x and z direction moving stages 3 and 4.

Since the gap between the tip of the probe and the surface of the vibrating portion of the wafer 6 is as narrow as several tens of μm, the linear probe 9 is used in which the accuracy and position accuracy of each probe shape are enhanced. In addition, the admittance measurement device
After the position adjustment of the x and y axes is completed, the signals from the respective probes of the linear probe 9 are sequentially switched and fetched, and each frequency is measured.

According to this embodiment, the frequency can be collectively measured in the horizontal direction or the vertical direction for each vibrating portion on the wafer, and the position adjustment in the y-axis direction is not required, so that the measurement time can be reduced. , The number of required stages can be reduced.

(Seventh Embodiment) Configuration Using Surface Probe In this embodiment, the configuration is shown in FIG. 7A and the structure of the surface probe is shown in FIGS. 7B and 7C. A planar probe 10 in which a probe is arranged,
The degrees of freedom of the driving system are set to two axes or one axis by the x and z direction moving stages 3 and 4.

For the same reason as in the sixth embodiment, a probe having a further improved shape and position accuracy is used. In addition, the admittance measuring device sequentially switches and takes in signals from the probes of the surface probe 10 after the position adjustment of the x and y axes is completed, and measures the respective frequencies.

According to the present embodiment, the frequency can be collectively measured vertically and horizontally for each vibrating portion on the wafer, so that the measurement time can be further reduced and the required number of stages can be minimized.

[0038]

As described above, according to the present invention, the relative position between the quartz wafer and the probe is adjusted by using the three-axis moving stage in the front, rear, left, right, up and down directions. Since the position is adjusted by using the stage and the position is adjusted by using the planar probe and the one-axis moving stage, the frequencies of all vibrating parts on the wafer are measured.

(1) In the process of manufacturing a crystal resonator by photolithography, an apparatus for entirely measuring the oscillation frequency in the vibrating portion of a crystal wafer is realized.

(2) The total number of oscillation frequencies of the crystal oscillator can be measured simply, quickly and accurately.

(3) Since the total number of vibration frequencies before and after or during etching can be measured, a fine etching process control corresponding to a higher frequency of the crystal oscillator can be performed.

(4) Without adding time and labor to the process, the frequency defect is significantly reduced by the total inspection of the oscillation frequency of the crystal oscillator, so that the yield in the etching process is greatly reduced. improves.

[Brief description of the drawings]

FIG. 1 shows a configuration using an xyz moving stage according to a first embodiment of the present invention.

FIG. 2 shows a configuration using a z-moving probe and an xy moving stage according to a second embodiment of the present invention.

FIG. 3 shows a configuration using a yz moving probe and an x moving stage according to a third embodiment of the present invention.

FIG. 4 shows a configuration using an xyz moving probe according to a fourth embodiment of the present invention.

FIG. 5 shows a configuration using a robot having four or more axes according to a fifth embodiment of the present invention.

FIG. 6 shows a configuration using a linear probe and a linear probe structure according to a sixth embodiment of the present invention.

FIG. 7 shows a configuration using a surface probe and a surface probe structure according to a seventh embodiment of the present invention.

FIG. 8 is a diagram illustrating a wafer structure and a principle of measuring a vibration frequency.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Y direction movement stage 2 ... Equipment housing 3 ... X direction movement stage 4 ... Z direction movement stage 5 ... Sample stage 6 ... Quartz wafer 7 ... Probe 8 ... Multi-axis robot 9 ... Linear probe 10 ... Surface probe

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Kaoru Kitasakizaki 2-1-1-17 Osaki, Shinagawa-ku, Tokyo Inside Meidensha Co., Ltd. (72) Takutaka Noguchi 2-1-1-17 Osaki, Shinagawa-ku, Tokyo No. Inside the company Meidensha

Claims (3)

[Claims] 1. An apparatus for manufacturing a crystal resonator in which a vibrating portion is formed vertically and horizontally on a quartz wafer by etching and a vibration frequency is adjusted by adjusting the thickness of each vibrating portion, wherein the crystal wafer is placed on a sample stage. A driving device for sequentially adjusting the position of the vibration frequency measurement probe in three axial directions with respect to each vibrating portion position, the sample stage having a counter electrode, and the driving device adjusting the position between the counter electrode and the probe; An apparatus for manufacturing a crystal resonator, comprising: an admittance measuring device that measures admittance of each vibrating part and obtains a vibration frequency of each vibrating part. 2. A manufacturing apparatus for a quartz oscillator, wherein a vibrating portion is formed on a quartz wafer vertically and horizontally by etching and a vibration frequency is adjusted by adjusting a thickness of each vibrating portion. A driving device that sequentially adjusts the relative position of the linear probe in which vibration frequency measuring probes are arranged in multiple channels in a linear manner with respect to each vibrating portion position, in the front-back or left-right direction and up-down direction, and It has an opposing electrode, and measures the admittance of each vibrating section in the horizontal or vertical direction, which is adjusted in position between the opposing electrode and each probe of the linear probe by the driving device, and measures the vibration. An apparatus for manufacturing a crystal unit, comprising: an admittance measuring device for obtaining a frequency. 3. An apparatus for manufacturing a crystal resonator in which a vibrating portion is formed vertically and horizontally on a quartz wafer by etching and a vibration frequency is adjusted by adjusting the thickness of each vibrating portion. A driving device that adjusts the relative position of the planar probe in which the vibration frequency measuring probes are arranged in multiple channels in a planar manner with respect to each vibrating portion position, in one axial direction in the vertical direction; and the sample stage has a counter electrode, An admittance measuring device for sequentially switching and measuring the admittance of each of the vibrating parts whose position is adjusted between the counter electrode and each probe of the planar probe by a driving device, and measuring the vibration frequency of each of the vibrating parts. A crystal oscillator manufacturing apparatus characterized by the above-mentioned.