Electrically heatable thin film getter and method for its preparation

Abstract

The application provides an electric heating type thin film getter and a preparation method thereof. The electric heating type thin film getter is composed of a base material and a surface getter material. The base material is vacuum dried after being cleaned by inorganic complex acid, then one or more layers of getter material are prepared on the surface of the base material by physical vapor deposition, and finally, the electric heating type thin film getter is obtained by vacuum annealing. The preparation method is simple and operable, and the prepared electric heating type thin film getter is flexible, simple and light in structure, convenient to assemble, good in film base bonding force, independently activatable, and high in gettering performance.

Description

Technical Field

[0001] This invention relates to the field of gas adsorption technology, specifically to an electrically heated thin-film getter and its preparation method. Background Technology

[0002] During the manufacturing, packaging, and use of vacuum electronic devices, reactive gases such as H2, CO, CO2, CH4, and H2O are generated inside the devices. These reactive gases mainly originate from residual gases within the device itself, outgassing from the casing and packaging materials, gas leakage from the casing, and gas leakage from the device. They can have varying degrees of impact on MEMS devices. For example, a decrease in vacuum level makes it difficult for infrared sensors to measure, and residual reactive gases can reduce the quality factor and signal-to-noise ratio of resonant micro electric field sensors.

[0003] Traditional solutions involve placing bulk getters inside the device. However, these bulk getters are bulky and prone to small particle detachment under external forces, leading to short circuits, significantly reducing device performance and shortening lifespan, making them unsuitable for miniaturized vacuum devices. Thin-film getters offer advantages such as high dimensional accuracy, high reliability, small size, and applicability at both the device and wafer levels, meeting the miniaturization needs of vacuum devices. Since device housings or caps are often irregularly shaped, current methods of directly depositing thin films on their surfaces using physical vapor deposition often result in uneven film thickness, low efficiency, and the need for tooling to protect uncoated areas during the deposition process, increasing costs. Summary of the Invention

[0004] To address the problems and shortcomings of existing technologies, this invention provides an electrically heated thin-film getter and its preparation method. This getter is characterized by its flexibility, simple and lightweight structure, ease of assembly, good film-substrate adhesion, independent activation, and high getter performance. Its preparation method is simple, highly operable, and has promising application prospects.

[0005] To solve the above-mentioned technical problems, the present invention provides an electrically heated thin-film getter, the preparation method of which includes:

[0006] The first step is to immerse the substrate material in an inorganic composite acid for cleaning and then vacuum dry it.

[0007] The second step involves preparing a getter alloy layer on the surface of the substrate material treated in the first step using physical vapor deposition, followed by vacuum annealing to obtain an electrically heated thin-film getter.

[0008] The matrix material can be W, Ta, Mo, Nb, nickel-chromium alloy, Pt, Cu, etc., and the thickness of the matrix material is 10-500 μm.

[0009] The inorganic composite acid cleaning solution is an aqueous solution of HF and HNO3, wherein the volume percentage of hydrofluoric acid is 1% to 10%, the volume percentage of nitric acid is 1% to 10%, and the acid cleaning time is 30 seconds to 3 minutes.

[0010] In the second step, the physical vapor deposition method uses sputtering to deposit the getter alloy layer, specifically bias sputtering. A positive or negative potential relative to the anode in the range of 0-500V is applied to the substrate to remove lightweight charged particles from the substrate during the coating process, thereby ensuring that the substrate is free of impure gases (e.g., residual gases such as H2O and N2).

[0011] The thickness of the getter alloy layer obtained in the second step is 0.5-5 μm.

[0012] The alloy material used in the gas-absorbing alloy layer is selected from one or more of titanium, zirconium, vanadium, iron, aluminum, copper, hafnium, chromium, manganese, lanthanum, cerium, praseodymium, and neodymium.

[0013] The vacuum annealing process in the second step is carried out at a temperature of 400℃ to 800℃ for a duration of 10 min to 60 min.

[0014] Beneficial effects of the present invention

[0015] The electrically heated thin-film getter proposed in this invention possesses excellent mechanical properties, good film-substrate bonding, strong adaptability, easy activation, and good getter performance. The preparation method is simple, highly operable, and has promising application prospects. Attached Figure Description

[0016] Figure 1 This is a structural schematic diagram (cross-sectional view) of the electrically heated thin-film getter of the present invention;

[0017] Figure 2 Gas-getting performance of electrically heated thin-film getters (test gas: H2). Detailed Implementation

[0018] The following embodiments and accompanying drawings are used to describe in detail the implementation of the present invention, so that the process of how the present invention uses technical means to solve technical problems and achieve technical effects can be fully understood and implemented accordingly.

[0019] This invention uses bias sputtering to deposit a getter alloy layer 2 on the surface of a substrate material 1, forming an electrically heated thin-film getter, as shown in the schematic diagram below. Figure 1 As shown.

[0020] Example 1

[0021] (1) Immerse a 50μm thick nickel-chromium alloy sheet in an inorganic composite acid solution (HF:HNO3:H2O=1:1:20, volume ratio) for 40s, then clean it with alcohol and deionized water for 3min each, and finally dry it with high-purity nitrogen.

[0022] (2) Thin films were prepared using bias sputtering. The cleaned nickel-chromium alloy sheet was placed in the coating chamber, and the Ti metal target was installed on the corresponding target position. The mechanical pump and molecular pump were turned on to evacuate the back vacuum of the coating system to 1.0 × 10⁻⁶. -6 ~1.0×10 -4 Pa, high-purity argon gas (99.99999%) is introduced into the chamber, substrate bias voltage is -100V, sputtering gas pressure is adjusted to stabilize at 0.5Pa, sputtering power is turned on to start pre-sputtering, pre-sputtering for 15min to ensure that the oxide layer on the target surface is completely removed, and then the getter film is deposited with sputtering power of 100W and deposition time of 60min to form a Ti getter layer with a thickness of 1μm;

[0023] (3) The nickel-chromium alloy sheet with the deposited getter alloy layer was vacuum treated at 600°C for 30 min to obtain an electrically heated thin film getter.

[0024] Example 2

[0025] (1) Immerse a 200μm thick molybdenum sheet in an inorganic composite acid solution (HF:HNO3:H2O=2:1:30, volume ratio) for 20s, then clean it with alcohol and deionized water for 3min each, and finally dry it with high-purity nitrogen.

[0026] (2) Thin films were prepared using bias sputtering. The cleaned nickel-chromium alloy sheet was placed in the coating chamber, and the ZrCoRE alloy target was installed on the corresponding target position. The mechanical pump and molecular pump were turned on to evacuate the back vacuum of the coating system to 1.0 × 10⁻⁶. -6 ~1.0×10 -4 Pa, high-purity argon gas (99.99999%) is introduced into the chamber, substrate bias voltage is -200V, sputtering gas pressure is adjusted and stabilized at 1Pa, sputtering power is turned on to start pre-sputtering, pre-sputtering for 15min to ensure that the oxide layer on the target surface is completely removed, and then the getter film is deposited with sputtering power of 100W and deposition time of 120min to form a ZrCoRE getter layer with a film thickness of 2μm;

[0027] (3) The molybdenum sheet with the deposited getter alloy layer was vacuum treated at 600°C for 30 min to obtain an electrically heated thin film getter.

[0028] Comparative Example

[0029] (1) Immerse a 50μm thick nickel-chromium alloy sheet in an inorganic composite acid solution (HF:HNO3:H2O=1:1:40, volume ratio) for 1 min, then clean it with alcohol and deionized water for 3 min each, and finally dry it with high-purity nitrogen.

[0030] (2) Thin films were prepared by magnetron sputtering. The cleaned nickel-chromium alloy sheet was placed in the coating chamber, and the ZrCoRE alloy target was installed on the corresponding target position. The mechanical pump and molecular pump were turned on to evacuate the back vacuum of the coating system to 1.0 × 10⁻⁶. -6 ~1.0×10 -4 Pa, high-purity argon gas (99.99999%) is introduced into the chamber, the sputtering pressure is adjusted and stabilized at 1 Pa, the sputtering power is turned on to start pre-sputtering, pre-sputtering for 15 min to ensure that the oxide layer on the target surface is completely removed, and then the getter film is deposited at a sputtering power of 100 W and a deposition time of 120 min to form a ZrCoRE getter layer with a film thickness of 2 μm, thus obtaining an electrically heated thin film getter.

[0031] All of the foregoing primary implementations of this intellectual property right do not limit other forms of implementation of this new product and / or new method. Those skilled in the art will utilize this important information to modify the foregoing to achieve similar implementations. However, all modifications or alterations based on this new product invention are reserved rights.

[0032] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention in any other way. Any person skilled in the art may make changes or modifications to the above-disclosed technical content to create equivalent embodiments. However, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A method for preparing an electrically heated thin-film getter, characterized in that, include: The first step involves immersing the flexible metal substrate material in an inorganic composite acid for cleaning and then vacuum drying. The second step involves preparing a getter alloy layer on the substrate material surface treated in the first step using a bias sputtering method. A positive or negative potential relative to the anode in the range of 100-500V is applied to the substrate, and vacuum annealing is performed. The vacuum annealing temperature is 400℃~800℃ and the treatment time is 10min~60min to obtain an electrically heated thin film getter. The substrate material is W, Ta, Mo, Nb, nickel-chromium alloy, Pt, or Cu; the inorganic composite acid cleaning solution is an aqueous solution of HF and HNO3.

2. The preparation method of the electrically heated thin-film getter as described in claim 1, characterized in that: The thickness of the substrate material is 10-500 μm.

3. The method for preparing the electrically heated thin-film getter as described in claim 1, characterized in that: The volume percentage of hydrofluoric acid is 1% to 10%, and the volume percentage of nitric acid is 1% to 10%.

4. The preparation method of the electrically heated thin-film getter as described in claim 1, characterized in that: The inorganic composite acid cleaning process takes 30 seconds to 3 minutes.

5. The method for preparing the electrically heated thin-film getter as described in claim 4, characterized in that: Applying a positive or negative potential relative to the anode in the range of 100-500V to the substrate removes lightweight charged particles from the substrate during the coating process, thereby ensuring that the substrate is free of impure gases.

6. The method for preparing the electrically heated thin-film getter as described in claim 1, characterized in that: The thickness of the getter alloy layer obtained in the second step is 0.5-5 μm.

7. The method for preparing the electrically heated thin-film getter as described in claim 1, characterized in that: The alloy material used in the getter alloy layer is selected from one or more of titanium, zirconium, vanadium, iron, aluminum, copper, hafnium, chromium, manganese, lanthanum, cerium, praseodymium, and neodymium.

8. An electrically heated thin-film getter prepared by any one of the preparation methods of claims 1 to 7.

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