阅读说明：本技术 人造石英晶体的优质籽晶片培育法 (High-quality seed crystal piece cultivation method for artificial quartz crystal ) 是由 刘盛浦 易际让 王晓刚 于 2019-11-14 设计创作，主要内容包括：本发明公开了一种人造石英晶体的优质籽晶片培育法,包括以下步骤：一、将待切割的人造石英晶体切割成只保留部分正负电轴区域的框架晶体；二、将框架晶体切割成框架籽晶片；三、将框架籽晶片置于高压釜内进行晶体生长；四、将框架晶体长出部分进行切割,得到优质籽晶片。本发明利用在石英晶体的+X方向(正电轴方向)长出的晶体不会遗传继承籽晶片上的缺陷的特点,进行优质籽晶片的培育,将长成部分的晶体进行籽晶片切割,从而得到低腐蚀隧道密度的优质籽晶片。(The invention discloses a method for cultivating high-quality seed crystal of artificial quartz crystal, which comprises the following steps: firstly, cutting an artificial quartz crystal to be cut into a frame crystal only reserving partial positive and negative electric axis areas; secondly, cutting the frame crystal into frame seed wafers; thirdly, placing the frame seed wafer in a high-pressure kettle for crystal growth; and fourthly, cutting the grown part of the frame crystal to obtain the high-quality seed crystal plate. The invention utilizes the characteristic that the crystal growing in the + X direction (positive electric axis direction) of the quartz crystal can not inherit the defect on the seed wafer to cultivate the high-quality seed wafer, and cuts the grown crystal into the seed wafer, thereby obtaining the high-quality seed wafer with low corrosion tunnel density.)

1. The high-quality seed crystal cultivating method for artificial quartz crystal includes the following steps:

firstly, cutting an artificial quartz crystal to be cut into a frame crystal only reserving partial positive and negative electric axis areas;

secondly, cutting the frame crystal into frame seed wafers;

thirdly, placing the frame seed wafer in a high-pressure kettle for crystal growth;

and fourthly, cutting the grown part of the frame crystal to obtain the high-quality seed crystal plate.

2. A method for growing a high-quality seed crystal of an artificial quartz crystal according to claim 1, wherein said first step is:

grinding the + X surface and the Z surface of the artificial quartz crystal to be cut to ensure that the orientation precision of the two ground planes is within +/-10'; the cut-out portion (1) is drawn on the other non-ground Z-plane and then cut.

3. A method for growing a high-quality seed crystal of an artificial quartz crystal according to claim 1 or 2, wherein the second step is a step of sequentially performing the following steps:

2.1, making a notch of the frame crystal downward, putting the cut part (1) in the step 1) back to the original position of the crystal, pouring a binder into a cutting gap, adhering the frame crystal to the cut part (1) and then adhering the frame crystal to a seed crystal cutting iron plate, enabling a-X part of the frame crystal to be upward and aligning to a frame-shaped metal knife rest of a multi-knife cutting machine, and arranging a cutting knife strip on the frame-shaped metal knife rest;

2.2, carrying out parallelism inspection on the frame-shaped metal tool rest and the seed crystal cutting iron plate so as to enable the movement error to be less than or equal to 0.05 mm; aiming at ensuring the parallelism of the cutting knife strip and the cut crystal;

2.3, preparing cutting fluid for the multi-knife cutting machine;

2.4, cutting the crystal by using a multi-cutter cutting machine under the coordination of cutting liquid, wherein the cutting speed is once to and fro every 4 seconds;

2.5, after the cutting knife strip of the multi-knife cutting machine cuts into the crystal (2 +/-0.2) mm, improving the cutting rate of the multi-knife cutting machine, and enabling the cutting rate to go and go once every 2 seconds; until the frame crystal is cut through;

2.6, putting the seed crystal cutting iron plate with the cut frame seed crystals into a sodium hydroxide solution for heating and soaking;

and 2.7, cleaning the obtained seed crystal to remove oil stains, and then removing the embedded part in the middle of the seed crystal to obtain the frame seed crystal wafer (2) in the shape of a Chinese character 'men'.

4. A method for growing a good-quality seed crystal of an artificial quartz crystal according to claim 3, wherein:

in the step 2.1, the adhesive is prepared from rosin: paraffin wax is 1:1 in mass ratio;

in the step 2.3, the 320-mesh green silicon carbide abrasive and the grinding cutting oil are mixed according to the weight ratio of 0.8:1 to obtain the cutting fluid.

5. A method of growing a high-quality seed crystal of an artificial quartz crystal according to claim 4, wherein:

in the step 2.6, each kilogram of water is added with (250 +/-25) grams of NaOH to obtain a sodium hydroxide solution;

heating to boiling and preserving heat for 30 +/-5 minutes so as to realize soaking.

6. A method for growing a high-quality seed crystal of an artificial quartz crystal according to claim 3, wherein said third step is:

the frame seed wafer (2) is first subjected to supersaturated NH as an etching solution₄HF₂Soaking and corroding (3 +/-0.5) hours in an ammonium bifluoride solution, and thenWashing with water and drying; then putting the quartz crystal into a high-pressure kettle, and carrying out crystal growth according to a hydrothermal temperature difference method of the artificial quartz crystal; a framework crystal was obtained.

7. A method for growing a good-quality seed crystal of an artificial quartz crystal according to claim 3, wherein said fourth step is:

4.1, cutting the frame crystal growing part 6 obtained in the step three according to the step one;

4.2, adhering the frame crystal growing part 6 obtained by cutting in the step 4.1 on a seed crystal cutting iron plate, wherein the part-X is upward and is aligned with a cutting tool bar of a multi-tool cutting machine;

then, operating according to 2.2-2.6;

and cleaning the cut seed crystal pieces, and removing oil stains to obtain the high-quality seed crystal piece of the artificial quartz crystal.

Technical Field

The invention relates to a high-quality seed crystal wafer cultivation process of an artificial quartz crystal, in particular to a frame-shaped + X-direction (positive electric axis direction) crystal growth and seed crystal wafer manufacturing technology of the artificial quartz crystal.

Background

The artificial quartz crystal has good piezoelectric and optical properties and is an important crystal material in the electronic and optical fields.

The artificial quartz crystal grows on the seed crystal by adopting a hydrothermal temperature difference method, the earliest seed crystal is formed by cutting the seed crystal from a natural quartz crystal, the seed crystal of the high-quality quartz crystal is more and more difficult to obtain from the nature along with the exhaustion of the mineral reserves of the high-quality natural quartz crystal, and the existing seed crystal is formed by cutting the artificial quartz crystal; however, due to the crystallization characteristics of the artificial quartz crystal, the defects on the seed crystal wafer are inherited into the grown crystal, and as the seed crystal wafer is continuously cut from the grown artificial quartz crystal, the lattice defects and the corrosion tunnel defects in the seed crystal wafer are more and more accumulated, so that the search for manufacturing the high-quality seed crystal wafer becomes an important research topic in the industry.

In the crystal growth process of the artificial quartz crystal by the hydrothermal temperature difference method, alkaline aqueous solution dissolved with silicon dioxide is convected to a low-temperature zone hung with a seed wafer to form supersaturated silicon dioxide to form crystallization growth on the surface of the seed wafer, according to the crystallization rule of the quartz crystal, the Z direction (optical axis direction) of the seed crystal is a main growth surface, the growth speed is fastest, the defect in the optical axis direction can be inherited to the grown crystal, and the +/-X direction (positive and negative electric axis directions) of the seed crystal also has certain growth.

The technical principle of the frame seed method is explained and confirmed in the document "New TECHNIQUE TO DECREASE DISLOCATION IN SYNTHETIC QUARTZ CRYSTAL", which however does not describe the specific processing of the frame seed wafer; therefore, how to operate to realize the high-quality seed crystal for cultivating the artificial quartz crystal is not known at present.

Disclosure of Invention

The invention aims to provide a high-quality seed crystal cultivation method for artificial quartz crystals.

In order to solve the technical problems, the invention provides a high-quality seed crystal cultivation method of an artificial quartz crystal, which comprises the following steps:

firstly, cutting an artificial quartz crystal to be cut into a frame crystal only reserving partial positive and negative electric axis areas;

secondly, cutting the frame crystal into a frame seed wafer, wherein the thickness of the frame seed wafer is generally 1-2 mm;

thirdly, placing the frame seed wafer in a high-pressure kettle for crystal growth;

and fourthly, cutting the grown part of the frame crystal to obtain a high-quality seed wafer (a low-defect high-quality seed wafer).

As an improvement of the high-quality seed crystal cultivation method of the artificial quartz crystal, the first step is as follows:

grinding the + X surface (positive axial surface) and a Z surface (optical axial surface) of the artificial quartz crystal to be cut to ensure that the orientation precision of the two ground planes is within +/-10'; the cut-out portion (1) is drawn on the other non-ground Z-plane (optical axis plane) and then cut.

Description of the drawings: the temperature of the cut part must be ensured not to exceed 573 ℃ in the cutting process;

drawing the width of the X area to be reserved according to different growing hills and area boundaries of the Z area and the X area on the unground Z surface (optical axis surface); the length direction of the cut-out portion 1 is the longest Y (mechanical axis) length within the crystal framework structure.

As a further improvement of the high-quality seed crystal cultivation method of the artificial quartz crystal, the second step is to sequentially carry out the following steps:

2.1, making a notch of a frame crystal downward, putting the cut part (1) in the step 1) back to the original position of the crystal, pouring a binder (such as a rosin paraffin solution) into a cutting gap, adhering the frame crystal to the cut part (1) and then adhering the frame crystal to a seed crystal cutting iron plate, enabling a negative electric shaft-X part of the frame crystal to be upward and aligning to a frame-shaped metal knife rest of a multi-knife cutting machine, and arranging a cutting knife strip on the frame-shaped metal knife rest;

2.2, carrying out parallelism inspection on the frame-shaped metal tool rest and the seed crystal cutting iron plate so as to enable the movement error to be less than or equal to 0.05 mm; aiming at ensuring the parallelism of the cutting knife strip and the cut crystal;

2.3, preparing cutting fluid for the multi-knife cutting machine;

2.4, cutting the crystal by using a multi-cutter cutting machine under the coordination of cutting liquid, wherein the cutting speed is once to and fro every 4 seconds;

2.5, after the cutting knife strip of the multi-knife cutting machine cuts into the crystal (2 +/-0.2) mm, improving the cutting rate of the multi-knife cutting machine, and enabling the cutting rate to go and go once every 2 seconds; until the frame crystal is cut through;

description of the drawings: after the frame seed crystal is cut through, reducing the running speed of the multi-cutter cutting machine to stop, closing the cutting liquid pump and the hydraulic pump, and lowering the seed crystal cutting iron plate stuck with quartz crystal;

2.6, putting the seed crystal cutting iron plate with the cut frame seed crystals into a sodium hydroxide solution for heating and soaking;

description of the drawings: the sodium hydroxide solution is added for soaking to remove heavy oil dirt of the cutting fluid, and the heating is used for melting the binder and the like;

and 2.7, cleaning the obtained seed crystal to remove oil stains (which can be realized by adopting conventional washing powder and detergent), and removing the embedded part in the middle of the seed crystal to obtain the door-shaped frame seed crystal wafer.

As a further improvement of the method for cultivating the high-quality seed crystal of the artificial quartz crystal,

in the step 2.1, the adhesive is prepared from rosin: paraffin wax is 1:1 in mass ratio;

in the step 2.3, the 320-mesh green silicon carbide abrasive and the grinding cutting oil are mixed according to the weight ratio of 0.8:1 to obtain the cutting fluid.

Description of the drawings: in step 2.1, the crystal is stuck on a seed crystal cutting iron plate, and HM306 quartz crystal special glue can be selected.

As a further improvement of the method for cultivating the high-quality seed crystal of the artificial quartz crystal,

in the step 2.6, each kilogram of water is added with (250 +/-25) grams of NaOH to obtain a sodium hydroxide solution;

heating to boiling and preserving heat for 30 +/-5 minutes so as to realize soaking.

As a further improvement of the high-quality seed crystal cultivation method of the artificial quartz crystal, the third step is as follows:

the frame seed wafer is first subjected to supersaturated NH as an etching solution₄HF₂Soaking and corroding (3 +/-0.5) hours in an ammonium bifluoride solution, washing with water and drying; then putting the quartz crystal into a high-pressure kettle, and carrying out crystal growth according to a hydrothermal temperature difference method of the artificial quartz crystal; obtaining the frame crystalAnd (3) a body.

As a further improvement of the high-quality seed crystal cultivation method of the artificial quartz crystal, the fourth step is:

4.1, cutting the frame crystal growing part 6 obtained in the third step like the first step;

4.2, adhering the frame crystal growing part 6 obtained by cutting in the step 4.1 on a seed crystal cutting iron plate, wherein the-X (negative electric axis) part is upward and is aligned with a cutting tool bar of a multi-tool cutting machine;

then, operating according to 2.2-2.6;

and cleaning the cut seed crystal pieces to remove oil stains (which can be realized by adopting conventional washing powder and detergent) to obtain the high-quality seed crystal piece of the artificial quartz crystal.

The length of the seed wafer to be cut is generally 200 to 300 mm.

The grown part of the frame crystal obtained by the invention is subjected to corrosion tunnel density test according to the specification of 4.2.8 in GB/T3352-2012 artificial quartz crystal specification and use guide; can be less than grade Ia specified in the Standard 4.1.5; 3 strips per square centimeter are achieved; and can therefore be referred to as a quality seed wafer.

The method comprises the specific steps of firstly cutting the artificial quartz crystal into a frame-shaped crystal only retaining part of positive and negative electric axis regions, then cutting the frame crystal into a frame seed wafer, then hanging the frame seed wafer into an autoclave for crystal growth, and cutting the part in the frame grown into the crystal again to obtain the high-quality seed wafer with low defects.

The invention relates to a method for manufacturing a high-quality seed wafer by adopting a frame crystal cultivation method. The invention discovers that: the growth direction in the + X direction (positive electric axis direction) is perpendicular to the optical axis direction, defects on the seed crystal are not inherited into the grown crystal, but the growth rate is slower than that in the Z direction (optical axis direction) and that in the-X direction (negative electric axis direction). The invention utilizes the characteristic that the crystal growing in the + X direction (positive electric axis direction) of the quartz crystal can not inherit the defects on the seed wafer to cultivate the high-quality seed wafer, and the grown crystal is subjected to seed wafer cutting to obtain the high-quality seed wafer with low corrosion tunnel density.

The invention utilizes an ultrahigh pressure (300-. Therefore, by adopting the method of the invention, the surface flatness of the cut seed crystal can reach 0.01-0.02 mm; the perpendicularity with the X surface can reach 90 degrees +/-10'.

Drawings

The following describes embodiments of the present invention in further detail with reference to the accompanying drawings.

FIG. 1 is a schematic view of an artificial quartz crystal.

FIG. 2 is a schematic axial view of a cut frame crystal.

Fig. 3 is a schematic view of a frame crystal after cutting is completed.

Fig. 4 is a schematic view of a frame crystal cutting seed.

Fig. 5 is a schematic view of a frame seed wafer after dicing and punching.

Fig. 6 is a schematic view of the suspension of the frame seed wafer on the seed holder.

Fig. 7 is a schematic view of a frame seed wafer grown crystal.

FIG. 8 shows a high-quality block of crystal obtained by cutting the + X (positive axis direction) extension 6 of the crystal of FIG. 7.

Fig. 9 shows a high quality seed wafer obtained by slicing the high quality crystal block 6 of fig. 8.

Detailed Description

The invention will be further described with reference to specific examples, but the scope of the invention is not limited thereto: