A method for preparing a KTP ceramic target

Abstract

The application provides a preparation method of a potassium titanyl phosphate (KTP) ceramic target. The core is that the powder obtained by grinding KTP crystals is sintered under heating and pressure to successfully prepare a dense and uniform polycrystalline KTP ceramic target. The main steps are as follows: first, the KTP crystals are ball milled into powder, which is sieved after grinding, then the binder polyvinyl alcohol (PVA) is added and put into a sintering furnace device for sintering to successfully prepare a dense and uniform polycrystalline KTP ceramic target. The technical path is provided for the preparation of the KTP target and the subsequent preparation of the KTP thin film.

Description

Technical Field

[0001] This application relates to the technical field of semiconductor materials, and in particular to a method for preparing a potassium titanium oxyphosphate (KTP) ceramic target. Background Technology

[0002] Potassium titanium oxyphosphate (KTiOPO4, or KTP for short) is a material with excellent nonlinear optical properties and electro-optic performance, and is therefore widely used in commercial and military fields. Significant progress was made in KTP crystal growth technology in the mid-to-late 1980s, further improving crystal quality. Currently, KTP crystals are widely used as frequency doubling materials inside and outside laser cavities. In addition, KTP also shows broad application prospects in optical parametric oscillation, electro-optic modulation, and medical / industrial green lasers.

[0003] In recent years, numerous studies both domestically and internationally have increasingly focused on KTP thin-film device research. However, the lack of high-purity KTP ceramic targets has hindered the fabrication of KTP thin-film devices. Therefore, the successful preparation of high-purity polycrystalline KTP ceramic targets is of great significance for the fabrication of KTP thin-film devices. Summary of the Invention

[0004] In view of this, this application proposes a method for preparing potassium titanium oxyphosphate (KTP) ceramic targets. This method aims to achieve the pressing and sintering of KTP powder through ball milling, sieving, granulation, pre-pressing and sintering, thereby successfully preparing polycrystalline high-purity KTP ceramic targets with a density greater than 90%, so as to overcome the lack of existing KTP ceramic targets.

[0005] To achieve the above objectives, this application provides a method for preparing potassium titanium oxyphosphate (KTP) ceramic targets, the method comprising the following steps:

[0006] Step S1. Add a certain proportion of balls and anhydrous ethanol to the KTP crystals and perform wet ball milling;

[0007] Step S2. The KTP slurry obtained after ball milling is dried, ground, and sieved. Then, a binder is added, and the mixture is granulated to form KTP.

[0008] powder;

[0009] Step S3. Pre-press the granulated powder into shape;

[0010] Step S4. Perform segmented heating sintering in an air atmosphere, and obtain the KTP ceramic target material after annealing.

[0011] Preferably, the ball milling step uses zirconia balls as the grinding medium, the ball-to-powder ratio is 3:1, the added liquid is anhydrous ethanol, the volume ratio of anhydrous ethanol to KTP powder is 3:1, and the ball milling time is 12 hours.

[0012] Preferably, the drying temperature is 75°C and the drying time is 24 hours.

[0013] Preferably, the sieve is 80 mesh.

[0014] Preferably, in the pre-compression molding step, the pressure used is 15~20MPa and the time is 3 minutes.

[0015] Preferably, the die size used for tableting can be either 0.5 inches or 1 inch.

[0016] Preferably, the sintering temperature adopts a segmented heating strategy, specifically as follows: first, the temperature is increased to 600°C at a rate of 2 min / °C and held for 3 hours; then, the temperature is increased to 1100°C at a rate of 2 min / °C and held for 2-3 hours; then, the temperature is annealed to 300°C at a rate of 2 min / °C; and finally, the temperature is cooled to room temperature.

[0017] The present invention also provides a KTP ceramic target material, which is obtained by the above preparation method. The KTP ceramic target material has a density greater than 90% and a grain size of 2~10 μm.

[0018] The method for preparing KTP ceramic targets of the present invention has the following beneficial effects:

[0019] The method for preparing KTP ceramic targets of the present invention uses KTP crystals as raw materials and obtains KTP ceramic targets through ball milling, sieving, granulation, pressing, and sintering. It has the advantages of simple process steps, ceramic target density greater than 90%, low sintering temperature, short sintering time, and low preparation cost. It solves the problem of the lack of KTP ceramic targets, has good prospects for industrial application, and provides a feasible way for the preparation of KTP thin film devices. Attached Figure Description

[0020] Figure 1 shows a cross-sectional SEM image of a KTP ceramic target sintered at 1100℃ in air atmosphere for 2.5 hours.

[0021] Figure 2 shows the XRD diffraction pattern of the KTP ceramic target sintered at 1100℃ in air atmosphere for 2.5 hours. Detailed Implementation

[0022] The preferred embodiments of the present invention will now be described in detail.

[0023] Example 1

[0024] Preparation of KTP ceramic target

[0025] Weigh two 5g portions of KTP crystals. Add 15g of zirconia balls and 15ml of anhydrous ethanol to each portion of KTP crystals. Place them diagonally in a ball mill for wet ball milling. After ball milling, dry the resulting KTP slurry at 75℃ for 24 hours. Then, grind and sieve it in a zirconia mortar using an 80-mesh sieve. Add a binder, polyvinyl alcohol (PVA), and granulate using an 80-mesh sieve to obtain KTP powder. Weigh 0.35g of the granulated powder and pre-press it in a 13mm diameter tablet press at 15MPa for 3 minutes. Finally, heat the tablet to 600℃ at a rate of 2min / ℃ in air and hold for 3 hours. Then, heat it to 1100℃ at a rate of 2min / ℃ and hold for 2.5 hours. After that, anneal the tablet to 300℃ at a rate of 2min / ℃ and finally cool it to room temperature to obtain the KTP ceramic target material. Figure 1 As shown, overall observation reveals that the sample exhibits a polycrystalline structure with fine-grained accumulation, good overall uniformity, no obvious large-sized abnormal grains or agglomerates, and a relatively high degree of densification. The grains are mainly equiaxed small grains, with a grain size of 2-10 μm. The grain boundaries are clear and there is no glass phase precipitation; only diffusely distributed nanoscale closed pores exist, without interconnected pores or microcracks. The XRD pattern of the KTP ceramic target is shown below. Figure 2 As shown, the horizontal axis is the 2θ angle and the vertical axis is the diffraction intensity. It can be seen that the characteristic diffraction peaks should present multiple sharp peaks with uniform intensity distribution. There is a strong diffraction peak at the 2θ angle of 27.22, which is determined to be the (131) crystal orientation by comparison with the standard card.

[0026] Example 2

[0027] Preparation of KTP ceramic target

[0028] The preparation method of the KTP ceramic target in this embodiment 2 is the same as that in embodiment 1, wherein the holding time at 1100℃ in this embodiment 2 is 2 hours.

[0029] Example 3

[0030] Preparation of KTP ceramic target

[0031] The preparation method of the KTP ceramic target in this embodiment 3 is the same as that in embodiment 1. In this embodiment 3, the heat treatment time at 1100°C is 3 hours.

[0032] Example 4

[0033] Preparation of KTP ceramic target

[0034] The preparation method of the KTP ceramic target in Example 4 is the same as that in Example 1, wherein the holding time at 1100℃ in Example 4 is 4 hours.

[0035] Finally, it should be noted that the above preferred embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail through the above preferred embodiments, those skilled in the art should understand that various changes can be made to it in form and detail without departing from the scope defined by the claims of the present invention.

Claims

1. A method for preparing a KTP ceramic target, characterized in that, The preparation method includes the following steps: Step S1. Add a certain proportion of balls and anhydrous ethanol to the KTP crystals and perform wet ball milling; Step S2. The KTP slurry obtained after ball milling is dried, ground, and sieved. Then, a binder is added, and the mixture is granulated to form KTP. powder; Step S3. Pre-press the granulated powder into shape; Step S4. Perform segmented heating sintering in an air atmosphere, and obtain the KTP ceramic target material after annealing.

2. The method for preparing the KTP ceramic target according to claim 1, characterized in that, In step S1, zirconium oxide balls are used as the grinding medium, the ball-to-powder ratio is 3:1, the volume ratio of anhydrous ethanol to KTP powder is 3:1, and the ball milling time is 12 hours.

3. The method for preparing the KTP ceramic target according to claim 1, characterized in that, In the pre-compression molding step, the pressure used is 15 MPa to 20 MPa, and the time is 3 minutes.

4. The method for preparing the KTP ceramic target according to claim 1, characterized in that, The segmented heating process is as follows: first, the temperature is increased to 600℃ at a rate of 2 min / ℃ and held for 3 hours; then, the temperature is increased to 1100℃ at a rate of 2 min / ℃ and held for 2 to 3 hours; then, the temperature is annealed to 300℃ at a rate of 2 min / ℃; and finally, the temperature is cooled to room temperature.

5. A KTP ceramic target material prepared according to the preparation method of any one of claims 1 to 4, characterized in that, The KTP ceramic target has a density greater than 90% and a grain size of 2 μm to 10 μm.

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