CN103952766B - A kind of method utilizing ion implanting to prepare potassium titanium oxide phosphate film - Google Patents

Abstract

The invention relates to a method for preparing a potassium titanyl phosphate film by ion implantation. The potassium titanyl phosphate crystals are respectively put into ethanol and acetone for ultrasonic cleaning treatment; low-energy light ions-H ions or He ions are implanted at room temperature Into the potassium titanyl phosphate material, the energy range of implanted ions is 100keV-300keV, and the implanted ion dose ranges from 1×10 ¹⁶ ions/cm² to 10×10 ¹⁶ ions/cm²; the material after the implantation of light ions is bound by resin glue Fix the material on the substrate, or directly bond the material after implanting light ions on the substrate, and the implanted surface sticks to the substrate; annealing is performed on the above-mentioned samples. This method can obtain a single crystal material with a better lattice structure; and this method does not have high requirements for the substrate material, and it is easy to realize bonding.

Description

A kind of method utilizing ion implantation to prepare potassium titanyl phosphate thin film

technical field

The invention relates to a method for preparing a potassium titanyl phosphate (KTiOPO ₄ ) film by ion implantation, and belongs to the technical field of nonlinear optical materials.

Background technique

In modern technology, optical devices gradually replace electronic devices in optical signal processing, because, compared with electronic devices, optoelectronic devices have many advantages, such as larger bandwidth, wavelength division multiplexing, etc., so more optoelectronic devices Integration into chips has become a hot research topic today. A waveguide structure with a large refractive index difference is a necessary condition for realizing highly integrated optical devices. There are many methods to fabricate waveguide structures, such as chemical vapor deposition, radio frequency sputtering, molecular beam epitaxy, and pulsed laser deposition, but these methods are difficult to produce high-quality single crystal structure materials. In addition, if the epitaxial growth method has restrictions on lattice matching, this has strict requirements on the substrate material. Potassium titanyl phosphate material has good nonlinear and electro-optic properties, and KTP thin film material can be widely used in nonlinear and optoelectronic integrated devices. The chemical composition of potassium titanyl phosphate crystal is KTiOPO ₄ , which is an oxide optical crystal with a relatively complex structure. It is difficult to obtain single crystal thin films by traditional thin film preparation techniques. Traditional KTP film preparation methods use chemical methods such as mechanical polishing, epitaxial growth, or ion exchange, which are very costly and the properties of films made by epitaxial or chemical methods cannot meet the requirements of single crystals. Ion implantation is a physical method, and the thickness of the film can be about submicron, and it retains the properties of the original single crystal material. These advantages cannot be achieved by other methods. So far, we have not used the ion implantation method to realize the relevant report of potassium titanyl phosphate thin film peeling.

Contents of the invention

The purpose of the present invention is to overcome the deficiencies of the prior art and provide a method for preparing a potassium titanyl phosphate film by ion implantation. The ion implantation and binding method is used to peel off the potassium titanyl phosphate film with a thickness of less than 1 micron.

The technical scheme that the present invention takes:

A kind of method utilizing ion implantation to prepare potassium titanyl phosphate film, comprises steps as follows:

(1) Put the potassium titanyl phosphate crystals into ethanol and acetone for ultrasonic cleaning treatment respectively, and blow dry with nitrogen;

(2) Implant low-energy light ions-H ions or He ions into the potassium titanyl phosphate material at room temperature. The implanted ion energy range is 100keV～300keV, and the implanted ion dose ranges from 1×10 ¹⁶ ions/square centimeter to 10 ×10 ¹⁶ ions/square centimeter; the implanted ion beam density is 3-4 microamps/square centimeter;

(3) Bind the light-ion-implanted material to the substrate through resin glue, or directly bond the light-ion-implanted material to the substrate, and stick the implanted surface to the substrate;

(4) Perform annealing treatment on the above samples in air, the annealing temperature is gradually increased from room temperature, the high temperature range of annealing is 200-600°C, and the total annealing time is 2-6 hours.

The light ion implantation surface described in step (2) in the above preparation method is a polished surface, and the implantation surface has two kinds of tangential directions, X tangential direction and Z tangential direction, both tangential directions are acceptable. Figure 1 shows schematic diagrams of samples in two different tangential directions, X and Z. Ions implanted under the same conditions into samples with different tangential directions will have different results. During the implantation process, the injection beam current range is required to be 3-4 microampere/square centimeter, so as to reduce the crystal surface damage caused by thermal deposition. The injection temperature was normal temperature. Selecting the energy of the implanted ions determines the thickness of the finally stripped film, the greater the energy, the greater the thickness of the film. The implantation energy involved in the present invention is small, and the thickness of the damaged layer is about 1 micron below the implanted surface, so that a relatively thin crystal material film can be peeled off. The larger the implant dose, the greater the induced lattice damage, which will increase the possibility of film peeling. But at the same time, the thermal effect caused by the high-dose implantation process may also promote the recovery of the damaged lattice. Therefore, it is necessary to try a variety of injection conditions to determine the best conditions to achieve film peeling. Preferably, the light ions are H ions implanted in the X tangential direction. The implanted ion energy range is preferably 100keV-200keV, and the implanted ion dose ranges from 5×10 ¹⁶ ions/cm² to 8×10 ¹⁶ ions/cm².

The composition of the resin glue mentioned in the above step (3) is: the epoxy resin and the hardener are mixed together according to the mass ratio of 10:1, so as to achieve good viscosity, and the epoxy resin and the hardener are conventional raw materials. The substrate we use is a silicon wafer or a silicon dioxide wafer. The thickness of the silicon wafer substrate material is about 0.5 mm, while the thickness of the sample is 1 mm. Therefore, we glue the two silicon substrates together with resin, It is then bonded to the injection surface of the sample to ensure that the thickness of the substrate is close to that of the sample. If the direct bonding method is used, that is, the cleaned KTP crystal injection surface is directly pressed with the cleaned substrate material, and the molecular force between the two materials is used to bind the two together, the smoothness and cleanliness of the sample surface will be greatly improved. There are high requirements for flatness, and the coefficient of thermal expansion of the substrate material must match that of the sample material.

In the annealing process described in the above step (4), the temperature starts at room temperature, and gradually increases the annealing temperature up to 600°C. Depending on the conditions of implantation, the appropriate annealing temperature is different. The total annealing time is 2-6 hours. During the annealing process, some samples will peel off automatically, while others need to apply a little external force, and the material film will peel off. The preferred condition of the annealing process is to rise from room temperature to 200° C., and the annealing time is 4 hours.

The steps of the method for making the potassium titanyl phosphate thin film are illustrated in FIG. 2 .

We implanted ions under different conditions into the X-tangential and Z-tangential potassium titanyl phosphate samples according to the above steps, and then carried out film stripping. Among them, the thin film exfoliation was achieved after injecting hydrogen ions (H ⁺ ) into the sample. Hydrogen ions with an energy of 117keV and a dose of 6×10 ¹⁶ ions/square centimeter were implanted along the Z crystal direction of the sample, and the film peeled off on the surface of the sample after the implantation was completed. There is no peeling phenomenon when hydrogen ions are implanted along the X crystal direction of the sample under the same conditions, but the next layer of film can still be peeled off through bonding and annealing. In Figure 3, there is a scanning electron microscope picture of the potassium titanyl phosphate film that we peeled off. The figure shows that the thickness of the film is more than 900 nanometers. After injecting different conditions of helium ions (He ⁺ ) into the sample, we observed a lot of cracks at the end of the ion range through transmission electron microscopy, indicating that if the sample is bound and annealed, the film peeling phenomenon should also occur .

^The present invention can produce thin films with high single- ^crystal characteristics by means of ^ion _implantation ^and binding. After the sample is bound to the substrate material and undergoes a series of annealing processes, the sample will be peeled off at the end of the ion implantation range, that is, the position where the damage is the largest, thereby peeling off the next layer of material with a better lattice structure film.

Compared with the existing methods for obtaining thin films of materials, the present invention has the advantages and positive effects that: a single crystal material with a better crystal lattice structure can be obtained by using ion implantation and annealing methods; and this method has no requirements for substrate materials High, it is easy to achieve binding. Through this method, we obtained potassium titanyl phosphate thin film with better single crystal properties. We detected the signal of the constituent elements of the sample by energy spectrometer, and the X-ray diffraction pattern of the thin film gave better single crystal diffraction peaks. It is shown that the exfoliated films have similar properties to single crystal KTP crystals. The X-ray diffraction spectrum of the film is shown in Figure 4. The peak position of the diffraction peak is consistent with that of a single crystal, and a wider diffraction peak means that the crystal structure is damaged. This is a common result caused by ion implantation into the crystal, and usually requires post-implantation annealing to eliminate it. Figure 5 is a transmission electron microscope image after implantation. It can be clearly seen that the crystal is broken in the implantation depth region, and this layer of crystal can be peeled off by means of bonding.

Description of drawings

Fig. 1 is used in the present invention X and Z two kinds of sample schematic diagrams of different tangents;

Fig. 2 is the method flowchart used in the present invention;

Fig. 3 is the topography diagram of 2# product in the embodiment 1 of the present invention.

Fig. 4 is the X-ray diffraction spectrum of the potassium titanyl phosphate film obtained by the present invention.

Fig. 5 is the transmission electron microscope picture of 13# product in embodiment 3 of the present invention.

detailed description

Below in conjunction with embodiment further illustrate. Wherein, the injection conditions in Example 1 are the same as those in Example 2, except that the tangential direction of the sample is different, the tangential direction of the sample in Example 1 is the X tangential direction, and the tangential direction of the sample in Example 2 is the Z tangential direction.

Example 1

H ions with an energy of ^117keV are implanted into the X-tangential potassium titanyl phosphate material ^at room temperature. The substrate is bound with resin glue and annealed. The annealing temperature is gradually increased from room temperature to 200°C. The total annealing time is 4 hours. The test results are as follows:

Sample serial number Implantation dose (ion/cm2) Film peeling 2# 6×10 ¹⁶ Successfully peeled off the film 3# 7×10 ¹⁶ Successfully peeled off the film

Example 2

H ions with an energy of ^117keV are implanted into the Z-tangential potassium titanyl phosphate material ^at room temperature. The substrate is bound with resin glue and annealed. The annealing temperature is gradually increased from room temperature to 200°C. The total annealing time is 2 hours. The test results are as follows:

Example 3

He ions with an energy of 200keV are implanted into the X and Z tangential potassium titanyl phosphate materials at room temperature, and the implantation dose ranges from 1×10 ¹⁶ ions/cm² to 10×10 ¹⁶ ions/cm²; after implantation, the sample Bond with the silicon substrate with resin glue and perform annealing treatment. The annealing temperature is gradually increased from room temperature to 600°C. The total annealing time: 6 hours. The test results are as follows:

Claims (5)

1. the method utilizing ion implanting to prepare potassium titanium oxide phosphate film, is characterized in that, comprises the following steps that

(1) potassium titanyl oxygenic phosphate(KTP) crystal is respectively put in ethanol and acetone after ultrasonic cleaning processes, dries up with nitrogen；

(2) by low-energy light ion H ion or He ion, it is injected at normal temperatures in potassium titanium oxide phosphate material, injects ion energy Weight range is 100keV～300keV, injects ion dose scope 1 × 10¹⁶Ion/square centimeter～10 × 10¹⁶Ion/square centimeter； Injecting ion beam current density is 3～4 μ A/cm²；

(3) material after injecting light ion is bundled on substrate by resin glue, and the material Direct Bonding after maybe injecting light ion exists On substrate, injection face is bonded on substrate；

(4) making annealing treatment above-mentioned sample in atmosphere, annealing temperature is stepped up by room temperature, and the high temperature range of annealing is 200～600 DEG C, anneal total time 2～6 hours；

Light ion injection face described in step (2) is burnishing surface, and injection face divide have two kinds tangential, X is tangential and Z is tangential.

A kind of method utilizing ion implanting to prepare potassium titanium oxide phosphate film the most according to claim 1, is characterized in that, step Suddenly the light ion described in (2) is H ion, is injected into X tangential.

A kind of method utilizing ion implanting to prepare potassium titanium oxide phosphate film the most according to claim 1, is characterized in that, note Enter ion energy range 100keV～200keV, inject ion dose scope 5 × 10¹⁶Ion/square centimeter～8 × 10¹⁶Ion/flat Square centimetre.

A kind of method utilizing ion implanting to prepare potassium titanium oxide phosphate film the most according to claim 1, is characterized in that, Step (3) is mentioned consisting of of resin glue: epoxy resin and curing agent mix according to mass ratio 10:1.

A kind of method utilizing ion implanting to prepare potassium titanium oxide phosphate film the most according to claim 1, is characterized in that, Annealing is to be raised to 200 DEG C from room temperature, and annealing time is 4 hours.