A powder metallurgy CrSi target material and preparation method thereof

Abstract

The present invention provides a powder metallurgy CrSi target material and a preparation method thereof. The chemical composition mass percentage of the powder metallurgy CrSi target material includes: Cr is 40-60wt%, Si is 40-60wt%. The preparation method comprises the following steps: (1) in a protective atmosphere, Cr powder and Si powder are mixed according to a formula amount, molded and compacted, and pre-pressed to obtain a mixed powder; (2) vacuum hot pressing and sintering the mixed powder obtained in step (1) to obtain a target blank; (3) cooling and post-processing the target blank obtained in step (2) to obtain the powder metallurgy CrSi target material. The powder metallurgy CrSi target material provided by the present invention has a density of 97% to 99%, a uniform microstructure, excellent target material processing performance, and a good and stable sputtering process, which can meet the use requirements.

Description

Technical Field

[0001] The invention belongs to the technical field of powder metallurgy materials, and relates to a powder metallurgy CrSi target material, and in particular to a powder metallurgy CrSi target material and a preparation method thereof. Background Art

[0002] At present, the integrated circuit industry is developing rapidly, and the demand for new target materials is increasing rapidly, especially various composite target materials, most of which need to be prepared using powder metallurgy, including Cr-Si alloy targets.

[0003] Powder metallurgy targets pay more attention to the uniformity of microstructure, because it is the key point that affects the sputtering performance and mechanical properties of the target. The sputtering performance affects the use effect of the target, and the mechanical properties affect the production and processing of the target. To obtain a uniform microstructure (complete grain growth, narrow size distribution, uniform distribution of alloy phases, no obvious aggregation of pores, etc.), the size distribution of the original powder particles is the key point.

[0004] Since the preparation process of powder metallurgy targets requires the mixing of metal and non-metal particles before sintering, if the particle size is too small, the powder activity will be large and alloying reaction will occur during the sintering process, resulting in defects such as empty bags, pore aggregation, and crack extension; if the particle size is too large, the pores are large, and sintering requires higher temperature and pressure to achieve densification, and larger grains are formed, which will cause stress concentration and cracking in the subsequent processing process, and the overall density is lower than that of fine-grained sintered targets. The distribution of powder particle size directly affects the preparation process of the target material, and then affects the processing and use performance. Combined with the current experience of preparing composite material targets by powder metallurgy, most processes choose the original material to keep the particle size the same or close, with a narrow particle size distribution, and do not consider the impact of grain size distribution on reaction activity, densification process, pore elimination, and final density during the preparation process.

[0005] CN 105328193A discloses a powder metallurgy target material and a manufacturing method thereof, which specifically discloses a Cr-Cu alloy target material for Schottky diode barriers in the field of discrete devices. The preparation method specifically includes: (1) batching: proportioning Cr powder and Cu powder raw materials according to the alloy composition of the powder metallurgy target material; (2) powder mixing: putting the two raw materials proportioned in step (1) into a mixer and mixing them evenly; (3) pressure sintering: pressure sintering the mixed powder obtained in step (2) into a target blank; (4) machining the target blank obtained in step (3) to prepare a Cr-Cu alloy monomer finished target material, or welding the machined monomer target material to a back plate to form a composite finished target. This patent mainly considers the influence of sintering pressure on the density of the target material during the preparation process, and does not reflect the influence of raw material particle size on the density of the target material. Summary of the invention

[0006] In view of the shortcomings of the prior art, the object of the present invention is to provide a powder metallurgy CrSi target material and a preparation method thereof. The powder metallurgy CrSi target material provided by the present invention has a high density, uniform microstructure, excellent target material processing performance, and exhibits good stability during sputtering, which can meet the use requirements.

[0007] To achieve this object, the present invention adopts the following technical solutions:

[0008] In a first aspect, the present invention provides a powder metallurgy CrSi target material, wherein the chemical composition weight percentages of the powder metallurgy CrSi target material include: Cr is 40-60wt% and Si is 40-60wt%.

[0009] The Cr content in the powder metallurgy CrSi target of the present invention is 40-60wt%, for example, it can be 42wt%, 46wt%, 50wt%, 54wt% or 58wt%, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0010] The Si content in the powder metallurgy CrSi target of the present invention is 40-60wt%, for example, it can be 42wt%, 46wt%, 50wt%, 54wt% or 58wt%, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0011] In the present invention, Cr and Si react with each other during the vacuum hot pressing process to generate stable phases of CrSi2 and CrSi, wherein a too high Cr content will lead to an increase in the required sintering temperature and easily generate unstable phases Cr5Si3 and CrSi3, affecting the acquisition of the material with the target phase composition, while a too low Cr content will lead to excessive Si and insufficient concentration of the Cr reactant, and the reaction cannot completely consume Si, causing the aggregation of single Si, more pores, and poorer overall uniformity and density of the material.

[0012] As a preferred technical solution of the present invention, the density of the powder metallurgy CrSi target is 97-99%, for example, it can be 97.2%, 97.4%, 97.6%, 97.8%, 98%, 98.2%, 98.4%, 98.6% or 98.8%, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0013] In a second aspect, the present invention provides a method for preparing the powder metallurgy CrSi target provided in the first aspect, the preparation method comprising the following steps:

[0014] (1) In a protective atmosphere, Cr powder and Si powder are mixed according to the formula, molded and compacted, and then pre-pressed to obtain a mixed powder;

[0015] (2) performing vacuum hot pressing sintering on the mixed powder obtained in step (1) to obtain a target material blank;

[0016] (3) Cooling and post-processing the target material blank obtained in step (2) to obtain the powder metallurgy CrSi target material.

[0017] The present invention uses multi-stage vacuum hot pressing sintering to make the density of the powder metallurgy target material more excellent and the microstructure uniform.

[0018] It is worth noting that the cooling in step (3) of the present invention includes: first cooling the target material blank to below 200° C., then taking it out, and then cooling it to room temperature.

[0019] As a preferred technical solution of the present invention, the purity of the Cr powder in step (1) is 99-99.9%, for example, it can be 99.1%, 99.2%, 99.3%, 99.4%, 99.5%, 99.6%, 99.7% or 99.8%, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0020] Preferably, the average particle size of the Cr powder in step (1) is 50-80 μm, for example, 55 μm, 60 μm, 65 μm, 70 μm or 75 μm, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0021] Preferably, the purity of the Si powder in step (1) is 99-99.9%, for example, it can be 99.1%, 99.2%, 99.3%, 99.4%, 99.5%, 99.6%, 99.7% or 99.8%, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0022] Preferably, the average particle size of the Si powder in step (1) is 5 to 15 μm, for example, 7 μm, 9 μm, 11 μm, 13 μm or 15 μm, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0023] The particle sizes of the Cr powder and Si powder described in the present invention will affect the phase composition, material density and pore number of the material after sintering; wherein, if the particle size of the Cr powder is too large, there will be too many pores, the diffusion of elements will be difficult during the sintering process of the material, the pore elimination process will be incomplete, and the density of the material after sintering will be too low; if the particle size is too small, the reaction activity will be too high, and the material will react violently with the Si powder during the sintering process, causing serious material shrinkage and deformation, and even producing large pore defects; if the particle size of the Si powder is too large, the reaction activity will decrease, the porosity will increase, and the Si particles will aggregate, making the sintering process incomplete, resulting in uneven distribution of components in the material; if the particle size is too small, the oxygen content will increase significantly, the material will increase in brittleness and easy to crack, and the increased reaction activity will make the sintering process difficult to control.

[0024] As a preferred technical solution of the present invention, the mixing in step (1) includes ball milling mixing.

[0025] Preferably, the rotation speed of the ball milling mixing is 300-400 r / min, for example, 320 r / min, 340 r / min, 360 r / min or 380 r / min, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0026] Preferably, the ball milling mixing time is 20 to 30 hours, for example, 22 hours, 24 hours, 26 hours or 28 hours, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0027] Preferably, the material-ball ratio in the ball milling mixture is (8-12):1, for example, it can be 8:1, 9:1, 10:1, 11:1 or 12:1, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0028] It is worth noting that in order to prevent air from contaminating the metal powder, the mixing process of the present invention is carried out in a protective gas.

[0029] As a preferred technical solution of the present invention, the end point of the mold compaction in step (1) is: the mold flatness ≤1.0mm, for example, it can be 0.9mm, 0.8mm, 0.7mm, 0.6mm, 0.5mm or 0.4mm, but is not limited to the listed values, and other values ​​not listed in the numerical range are also applicable.

[0030] Preferably, the pre-pressing pressure in step (1) is 20-40T, for example, it can be 22T, 24T, 26T, 28T, 30T, 32T, 34T, 36T or 38T, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0031] As a preferred technical solution of the present invention, the vacuum hot pressing sintering in step (2) includes.

[0032] Vacuum to 10 -2 Pa, and then perform one-stage hot pressing sintering, two-stage hot pressing sintering, three-stage hot pressing sintering and pressure treatment in sequence.

[0033] The purpose of multiple hot pressing sintering in the present invention is to allow the powder to have sufficient time to react and achieve densification at different stages of the sintering process, so as to obtain a material with complete reaction, uniform structure and good density. The first stage of hot pressing sintering can fully form the sintering neck between particles in the low temperature stage, and the point contact between the powders is transformed into surface contact, the volume shrinks slightly, and a part of the air in the pores is eliminated. The second stage of hot pressing sintering can make the sintering neck grow and further reduce the distance between particles, most of the pores gradually disappear, the volume shrinks and the density is improved. The third stage of hot pressing sintering can fully form the CrSi phase and CrSi2 phase in the material, and close and shrink the pores between the particles to form a uniform and dense CrSi target material.

[0034] Preferably, the one-stage hot pressing sintering comprises: increasing the pressure at a first pressure increasing rate, increasing the temperature to a first temperature at a first temperature increasing rate, stopping the pressure increasing and performing a first temperature keeping and pressure keeping.

[0035] Preferably, the two-stage hot pressing sintering comprises: increasing the pressure at a second pressure increasing rate, increasing the temperature to a second temperature at a second temperature increasing rate, and performing a second heat preservation.

[0036] It is worth noting that in the two-stage hot pressing sintering process described in the present invention, the pressure is continuously increased at the second pressure increase rate during the heat preservation stage.

[0037] Preferably, the three-stage hot pressing sintering comprises: increasing the pressure at a third pressure increasing rate, increasing the temperature to a third temperature at a second temperature increasing rate, stopping the pressure increasing and performing a third heat preservation.

[0038] Preferably, the end point of the pressurization treatment: the pressure in the reactor is -0.06MPa to -0.08MPa, for example, -0.06MPa, -0.065MPa, -0.07MPa or -0.075MPa, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0039] As a preferred technical solution of the present invention, the first heating rate is 2 to 6°C / min, for example, it can be 2°C / min, 3°C / min, 4°C / min, 5°C / min or 6°C / min, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0040] Preferably, the first boost rate is 2 to 6 T / min, for example, 2 T / min, 3 T / min, 4 T / min, 5 T / min or 6 T / min, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0041] Preferably, the first temperature is 500-600°C, for example, 520°C, 540°C, 560°C or 580°C, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0042] Preferably, the first insulation and pressure holding time is 1 to 3 hours, for example, it can be 1.2h, 1.4h, 1.6h, 1.8h, 2h, 2.2h, 2.4h, 2.6h or 2.8h, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0043] Preferably, the second boost rate is 0.5-3 T / min, for example, 0.8 T / min, 1.2 T / min, 1.6 T / min, 2 T / min, 2.4 T / min or 2.8 T / min, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0044] Preferably, the second heating rate is 0.5-5°C / min, for example, 1°C / min, 2°C / min, 3°C / min or 4°C / min, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0045] Preferably, the second temperature is 700-800°C, for example, 720°C, 740°C, 760°C or 780°C, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0046] Preferably, the second insulation time is 1 to 2 hours, for example, 1 hour, 1.2 hours, 1.4 hours, 1.6 hours, 1.8 hours or 2 hours, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0047] Preferably, the third boost rate is 0.5-3 T / min, for example, it can be 0.8 T / min, 1.2 T / min, 1.6 T / min, 2 T / min, 2.4 T / min or 2.8 T / min, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0048] Preferably, the third heating rate is 0.5-5°C / min, for example, 1°C / min, 2°C / min, 3°C / min or 4°C / min, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0049] Preferably, the third temperature is 850-1000°C, for example, it can be 870°C, 890°C, 910°C, 930°C, 950°C, 970°C or 990°C, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0050] Preferably, the third insulation and pressure holding time is 150 to 240 minutes, for example, it can be 150 minutes, 170 minutes, 190 minutes, 210 minutes or 230 minutes, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0051] As a preferred technical solution of the present invention, the post-processing in step (3) includes any one of grinding, wire cutting or polishing, or a combination of at least two of them.

[0052] As a preferred technical solution of the present invention, the method described in the powder metallurgy CrSi target material provided in the second aspect of the present invention comprises the following steps:

[0053] (1) Under a protective atmosphere, Cr powder with a purity of 99-99.9% and an average particle size of 50-80 μm and Si powder with a purity of 99-99.9% and an average particle size of 5-15 μm are mixed according to the formula, molded and compacted to a mold flatness of ≤1.0 mm, and then pre-pressed to a pressure of 20-40T to obtain a mixed powder;

[0054] Wherein, the mixing includes ball milling mixing; the rotation speed of the ball milling mixing is 300-400 r / min, the time is 20-30 h, and the material-ball ratio is (8-12):1;

[0055] (2) performing vacuum hot pressing sintering on the mixed powder obtained in step (1) to obtain a target material blank;

[0056] Wherein, the vacuum hot pressing sintering comprises: vacuumizing to 10 -2 Pa, and then carry out one-stage hot pressing sintering, two-stage hot pressing sintering, three-stage hot pressing sintering and pressurizing treatment in sequence until the pressure in the reactor is -0.06MPa~-0.08MPa;

[0057] The one-stage hot pressing sintering comprises: increasing the pressure at a first pressure increasing rate of 2 to 6 T / min, increasing the temperature to 500 to 600° C. at a first heating rate of 2 to 6° C. / min, stopping the pressure increasing and performing a first heat preservation and pressure holding for 1 to 3 hours;

[0058] The two-stage hot pressing sintering includes: increasing the pressure at a second increasing pressure rate of 0.5 to 3 T / min, increasing the temperature to 700 to 800° C. at a second increasing temperature rate of 0.5 to 5° C. / min, and performing a second heat preservation for 1 to 2 hours;

[0059] The three-stage hot pressing sintering includes: increasing the pressure at a third increasing pressure rate of 0.5 to 3T / min, increasing the temperature to 850 to 1000°C at a second increasing temperature rate of 0.5 to 5°C / min, stopping the pressure increase and performing a third heat preservation period of 150 to 240 minutes;

[0060] (3) Cooling and post-processing the target material blank obtained in step (2) to obtain the powder metallurgy CrSi target material.

[0061] The numerical range described in the present invention not only includes the point values ​​listed above, but also includes any point values ​​between the above numerical ranges that are not listed. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0062] Compared with the prior art, the present invention has the following beneficial effects:

[0063] (1) The density of the powder metallurgy CrSi target provided by the present invention reaches 97-99%, and the microstructure is uniform;

[0064] (2) The powder metallurgy CrSi target material provided by the present invention has excellent processing performance, and the sputtering process performs well and stably, which can meet the use requirements. DETAILED DESCRIPTION

[0065] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0066] Example 1

[0067] The present embodiment provides a powder metallurgy CrSi target material, wherein the chemical composition weight percentages of the powder metallurgy CrSi target material include: Cr is 50wt% and Si is 50wt%.

[0068] The preparation method of the powder metallurgy CrSi target comprises the following steps:

[0069] (1) Under a protective atmosphere, Cr powder with a purity of 99.5% and an average particle size of 75 μm and Si powder with a purity of 99.5% and an average particle size of 10 μm are mixed according to the formula, compacted in a mold until the mold flatness is 0.8 mm, and then pre-pressed to a pressure of 30 T to obtain a mixed powder;

[0070] The mixing includes ball milling; the speed of the ball milling is 350 r / min, the time is 25 h, and the material-to-ball ratio is 10:1;

[0071] (2) performing vacuum hot pressing sintering on the mixed powder obtained in step (1) to obtain a target material blank;

[0072] Wherein, the vacuum hot pressing sintering comprises: vacuumizing to 10 -2 Pa, and then carry out the first stage hot pressing sintering, the second stage hot pressing sintering, the third stage hot pressing sintering and pressurizing treatment in sequence until the pressure in the reactor is -0.07MPa;

[0073] The one-stage hot pressing sintering comprises: increasing the pressure at a first pressure increase rate of 4 T / min, increasing the temperature to 550° C. at a first temperature increase rate of 4° C. / min, stopping the pressure increase and performing a first heat preservation and pressure holding for 2 hours;

[0074] The two-stage hot pressing sintering includes: increasing the pressure at a second increasing pressure rate of 2.1 T / min, increasing the temperature to 750° C. at a second increasing temperature rate of 2.25° C. / min, and performing a second heat preservation for 1.5 hours;

[0075] The three-stage hot pressing sintering includes: increasing the pressure at a third increasing rate of 1.75 T / min, increasing the temperature to 920° C. at a second increasing rate of 2.25° C. / min, stopping the pressure increase and performing a third heat preservation period of 190 min;

[0076] (3) Cooling and post-processing the target material blank obtained in step (2) to obtain the powder metallurgy CrSi target material.

[0077] Example 2

[0078] The present embodiment provides a powder metallurgy CrSi target material, wherein the chemical components by weight percentage of the powder metallurgy CrSi target material include: 40 wt % of Cr and 60 wt % of Si.

[0079] The preparation method of the powder metallurgy CrSi target comprises the following steps:

[0080] (1) Under a protective atmosphere, Cr powder with a purity of 99% and an average particle size of 50 μm and Si powder with a purity of 99% and an average particle size of 5 μm are mixed according to the formula, compacted into a mold until the mold flatness is 1.0 mm, and then pre-pressed to a pressure of 20 T to obtain a mixed powder;

[0081] The mixing includes ball milling; the speed of the ball milling is 300 r / min, the time is 30 h, and the material-ball ratio is 12:1;

[0082] (2) performing vacuum hot pressing sintering on the mixed powder obtained in step (1) to obtain a target material blank;

[0083] Wherein, the vacuum hot pressing sintering comprises: vacuumizing to 10 -2 Pa, and then carry out one-stage hot pressing sintering, two-stage hot pressing sintering, three-stage hot pressing sintering and pressurization treatment in sequence until the pressure in the reactor is -0.06MPa;

[0084] The one-stage hot pressing sintering includes: increasing the pressure at a first pressure increase rate of 2T / min, increasing the temperature to 500°C at a first temperature increase rate of 2°C / min, stopping the pressure increase and performing a first heat preservation and pressure holding period of 3h;

[0085] The two-stage hot pressing sintering includes: increasing the pressure at a second pressure increase rate of 0.5 T / min, increasing the temperature to 700° C. at a second temperature increase rate of 0.5° C. / min, and performing a second heat preservation for 2 hours;

[0086] The three-stage hot pressing sintering includes: increasing the pressure at a third increasing pressure rate of 0.5 T / min, increasing the temperature to 850° C. at a second increasing temperature rate of 0.5° C. / min, stopping the pressure increase and performing a third heat preservation period of 240 minutes;

[0087] (3) Cooling and post-processing the target material blank obtained in step (2) to obtain the powder metallurgy CrSi target material.

[0088] Example 3

[0089] The present embodiment provides a powder metallurgy CrSi target material, wherein the chemical components by weight percentage of the powder metallurgy CrSi target material include: Cr is 60wt% and Si is 40wt%.

[0090] The preparation method of the powder metallurgy CrSi target comprises the following steps:

[0091] (1) Under a protective atmosphere, Cr powder with a purity of 99.9% and an average particle size of 80 μm and Si powder with a purity of 99.9% and an average particle size of 15 μm are mixed according to the formula, compacted into a mold until the mold flatness is 0.5 mm, and then pre-pressed to a pressure of 40 T to obtain a mixed powder;

[0092] The mixing includes ball milling; the speed of the ball milling is 400 r / min, the time is 20 h, and the material-ball ratio is 8:1;

[0093] (2) performing vacuum hot pressing sintering on the mixed powder obtained in step (1) to obtain a target material blank;

[0094] Wherein, the vacuum hot pressing sintering comprises: vacuumizing to 10 -2 Pa, and then carry out one-stage hot pressing sintering, two-stage hot pressing sintering, three-stage hot pressing sintering and pressurization treatment in sequence until the pressure in the reactor is -0.08MPa;

[0095] The one-stage hot pressing sintering includes: increasing the pressure at a first pressure increase rate of 6 T / min, increasing the temperature to 600° C. at a first temperature increase rate of 6° C. / min, stopping the pressure increase and performing a first heat preservation and pressure holding period of 1 hour;

[0096] The two-stage hot pressing sintering includes: increasing the pressure at a second increasing pressure rate of 3T / min, increasing the temperature to 800°C at a second increasing temperature rate of 5°C / min, and performing a second heat preservation for 1 hour;

[0097] The three-stage hot pressing sintering includes: increasing the pressure at a third increasing pressure rate of 3T / min, increasing the temperature to 1000°C at a second increasing temperature rate of 5°C / min, stopping the pressure increase and performing a third heat preservation period of 150min;

[0098] (3) Cooling and post-processing the target material blank obtained in step (2) to obtain the powder metallurgy CrSi target material.

[0099] Example 4

[0100] The present embodiment provides a powder metallurgy CrSi target material, wherein the chemical composition weight percentages of the powder metallurgy CrSi target material include: Cr is 50wt% and Si is 50wt%.

[0101] The preparation method of the powder metallurgy CrSi target material is different from that of Example 1 only in that:

[0102] In this embodiment, the pre-pressing pressure in step (1) is modified to 15T.

[0103] Example 5

[0104] The present embodiment provides a powder metallurgy CrSi target material, wherein the chemical composition weight percentages of the powder metallurgy CrSi target material include: Cr is 50wt% and Si is 50wt%.

[0105] The preparation method of the powder metallurgy CrSi target material is different from that of Example 1 only in that:

[0106] In this embodiment, the pre-pressing pressure in step (1) is modified to 45T.

[0107] Example 6

[0108] The present embodiment provides a powder metallurgy CrSi target material, wherein the chemical composition weight percentages of the powder metallurgy CrSi target material include: Cr is 50wt% and Si is 50wt%.

[0109] The preparation method of the powder metallurgy CrSi target material is different from that of Example 1 only in that:

[0110] In this embodiment, the first pressure increase rate of the hot pressing sintering in step (2) is modified to 1.5 T / min, and the heating rate is modified to 1.5° C. / min.

[0111] Example 7

[0112] The present embodiment provides a powder metallurgy CrSi target material, wherein the chemical composition weight percentages of the powder metallurgy CrSi target material include: Cr is 50wt% and Si is 50wt%.

[0113] The preparation method of the powder metallurgy CrSi target material is different from that of Example 1 only in that:

[0114] In this embodiment, the first temperature in step (2) is modified to 450°C.

[0115] Example 8

[0116] The present embodiment provides a powder metallurgy CrSi target material, wherein the chemical composition weight percentages of the powder metallurgy CrSi target material include: Cr is 50wt% and Si is 50wt%.

[0117] The preparation method of the powder metallurgy CrSi target material is different from that of Example 1 only in that:

[0118] In this embodiment, the first temperature in step (2) is modified to 650°C.

[0119] Example 9

[0120] The present embodiment provides a powder metallurgy CrSi target material, wherein the chemical composition weight percentages of the powder metallurgy CrSi target material include: Cr is 50wt% and Si is 50wt%.

[0121] The preparation method of the powder metallurgy CrSi target material is different from that of Example 1 only in that:

[0122] In this embodiment, the second pressure increase rate in the two-stage hot pressing sintering process of step (2) is modified to 5T / min, and the second heating rate is modified to 6°C / min.

[0123] Example 10

[0124] The present embodiment provides a powder metallurgy CrSi target material, wherein the chemical composition weight percentages of the powder metallurgy CrSi target material include: Cr is 50wt% and Si is 50wt%.

[0125] The preparation method of the powder metallurgy CrSi target material is different from that of Example 1 only in that:

[0126] In this embodiment, the third pressure increase rate in the three-stage hot pressing sintering process of step (2) is modified to 5T / min, and the third heating rate is modified to 6°C / min.

[0127] Embodiment 11

[0128] The present embodiment provides a powder metallurgy CrSi target material, wherein the chemical composition weight percentages of the powder metallurgy CrSi target material include: Cr is 50wt% and Si is 50wt%.

[0129] The preparation method of the powder metallurgy CrSi target material is different from that of Example 1 only in that:

[0130] In this embodiment, the second temperature described in step (2) is modified to 850°C.

[0131] Example 12

[0132] The present embodiment provides a powder metallurgy CrSi target material, wherein the chemical composition weight percentages of the powder metallurgy CrSi target material include: Cr is 50wt% and Si is 50wt%.

[0133] The preparation method of the powder metallurgy CrSi target material is different from that of Example 1 only in that:

[0134] In this embodiment, the third temperature in step (2) is modified to 1100°C.

[0135] Embodiment 13

[0136] The present embodiment provides a powder metallurgy CrSi target material, wherein the chemical composition weight percentages of the powder metallurgy CrSi target material include: Cr is 50wt% and Si is 50wt%.

[0137] The preparation method of the powder metallurgy CrSi target material is different from that of Example 1 only in that:

[0138] In this embodiment, the two-stage hot pressing sintering process described in step (2) is omitted.

[0139] Embodiment 14

[0140] The present embodiment provides a powder metallurgy CrSi target material, wherein the chemical composition weight percentages of the powder metallurgy CrSi target material include: Cr is 50wt% and Si is 50wt%.

[0141] The preparation method of the powder metallurgy CrSi target material is different from that of Example 1 only in that:

[0142] In this embodiment, the particle size of the Cr powder in step (1) is modified to 40 μm.

[0143] Embodiment 15

[0144] The present embodiment provides a powder metallurgy CrSi target material, wherein the chemical composition weight percentages of the powder metallurgy CrSi target material include: Cr is 50wt% and Si is 50wt%.

[0145] The preparation method of the powder metallurgy CrSi target material is different from that of Example 1 only in that:

[0146] In this embodiment, the particle size of the Cr powder in step (1) is modified to 90 μm.

[0147] Example 16

[0148] The present embodiment provides a powder metallurgy CrSi target material, wherein the chemical composition weight percentages of the powder metallurgy CrSi target material include: Cr is 50wt% and Si is 50wt%.

[0149] The preparation method of the powder metallurgy CrSi target material is different from that of Example 1 only in that:

[0150] In this embodiment, the particle size of the Si powder in step (1) is modified to 3 μm.

[0151] Embodiment 17

[0152] The present embodiment provides a powder metallurgy CrSi target material, wherein the chemical composition weight percentages of the powder metallurgy CrSi target material include: Cr is 50wt% and Si is 50wt%.

[0153] The preparation method of the powder metallurgy CrSi target material is different from that of Example 1 only in that:

[0154] In this embodiment, the particle size of the Si powder in step (1) is modified to 20 μm.

[0155] Comparative Example 1

[0156] This comparative example provides a powder metallurgy CrSi target material, wherein the chemical components by weight percentage of the powder metallurgy CrSi target material include: 30 wt % of Cr and 70 wt % of Si.

[0157] The preparation method of the powder metallurgy CrSi target is the same as that in Example 1.

[0158] Comparative Example 2

[0159] This comparative example provides a powder metallurgy CrSi target material, wherein the chemical components by weight percentage of the powder metallurgy CrSi target material include: Cr is 70wt% and Si is 30wt%.

[0160] The preparation method of the powder metallurgy CrSi target is the same as that in Example 1.

[0161] Performance testing:

[0162] The relevant test results of the powder metallurgy CrSi target provided in the above embodiments and comparative examples are shown in Table 1.

[0163] Table 1

[0164]

[0165]

[0166] From Table 1, we can see the following points:

[0167] (1) Based on Examples 1-3, it can be seen that the density of the powder metallurgy CrSi target provided by the present invention reaches 97% to 99%, the microstructure is uniform, the target processing performance is excellent, the sputtering process is good and stable, and it can meet the use requirements;

[0168] (2) Analysis of Examples 1, 4-5 shows that the pre-pressing pressure will affect the density of the target blank and the uniformity of the target material. Appropriate pressure during the pre-pressing process will reduce the gaps between the powders, increase the density, and facilitate the elimination of pores during the subsequent hot pressing process. When the pre-pressing pressure is small, the residual pores between the powders are large, and the degree of densification is weakened. At the same time, due to the large number of pores between the powder particles, the powder shrinks severely as a whole during the vacuum hot pressing process, resulting in poor target uniformity. Increasing the pre-pressing pressure is beneficial to the densification and uniformity of the target material, but after the pressure is increased to a certain level, the effect of continuing to increase the pressure on the densification and uniformity is not obvious;

[0169] (3) Analysis of Examples 1, 6-8 shows that the heating rate of a hot pressing stage affects the density of the target material, and the temperature of a hot pressing stage has little effect on the uniformity. The increase in the heating rate reduces the overall time of a hot pressing process, resulting in incomplete formation of sintering necks by the powders, and a portion of the powders do not change from point contact to surface contact, which increases the pressure of the later densification process and causes incomplete subsequent densification;

[0170] (4) Analysis of Examples 1, 9-10 shows that increasing the heating rate of the second-stage hot pressing has little effect on the density of the target material, while a too fast heating rate of the third-stage hot pressing will lead to poor density and uniformity of the target material. The main purpose of the second-stage hot pressing is to provide energy for the growth of the powder sintering neck, pore shrinkage, and grain growth in the middle stage of powder sintering. The shrinkage and densification process of the target material mainly occurs in the second-stage hot pressing. Regarding Example 9, the heating rate of the second-stage hot pressing is increased. Since the overall temperature of the second-stage hot pressing process has not reached the sintering temperature, changing the second-stage heating process will not have too much impact on the overall uniformity of the target material; Regarding Example 10, the heating rate of the third-stage hot pressing is increased. At this time, the target material is close to the sintering temperature. A too fast heating rate can easily lead to different temperatures at the edge and core of the target material. Under the same insulation time, the edge has become dense, and the core is poorly densified, which makes the overall density and uniformity of the target material worse;

[0171] (5) Analysis of Examples 1, 11-13 shows that if the second-stage hot pressing sintering temperature is too high, the density and uniformity of the target material will be deteriorated. If the third-stage hot pressing temperature is increased, the density and uniformity of the target material will be slightly affected. If the second-stage hot pressing temperature is too high, the pore pressure will increase during the pore shrinkage process, the grain growth rate will be too fast, and the density will decrease. If the third-stage hot pressing temperature is increased, the densification process will not be affected, but the high temperature will easily cause some parts to be overburned to a certain extent, affecting the overall uniformity of the target material.

[0172] (6) Analysis of Examples 1, 14-17 shows that, when the Si powder particle size is consistent, Cr powder particle size that is too coarse or too fine will cause a decrease in the density and uniformity of the target material. If the powder particle size is too large, the surface energy of the powder particles is small, and the low sintering activity can easily lead to insufficient densification, poor powder uniformity during the mixing process, and poor target uniformity after sintering; the smaller the powder particles, the greater the specific surface energy, the easier it is to adsorb impurity elements, the more violent the reaction, the pores gather during the reaction, the product shrinks severely, and it is easy to cause excessive defects inside the target material. The appropriate particle size can make the mixing effect better and the sintering more uniform. There are fewer gaps after the powder is filled, and the degree of densification is higher;

[0173] (7) Analysis of Example 1, Comparative Example 1, and Comparative Example 2 shows that, under certain process conditions, too much or too little Cr powder content will cause a decrease in the density and uniformity of the target material. Too high a Cr content will increase the required sintering temperature, and the target blank as a whole will not reach the densification temperature, resulting in a poor degree of densification. Too low a Cr content will lead to excessive Si, and the reaction will not be able to completely consume Si, causing the aggregation of single Si, more pores, and poor overall uniformity and density of the material.

[0174] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing a powder metallurgy CrSi target, characterized in that: The preparation method comprises the following steps: (1) In a protective atmosphere, Cr powder and Si powder are mixed in a formula of 40-60wt% Cr and 40-60wt% Si, and the mixture is pre-pressed after being molded and compacted to obtain a mixed powder; (2) performing vacuum hot pressing sintering on the mixed powder obtained in step (1) to obtain a target material blank; (3) cooling and post-processing the target material blank obtained in step (2) to obtain the powder metallurgy CrSi target material; The average particle size of the Cr powder in step (1) is 50 to 80 μm; The average particle size of the Si powder in step (1) is 5 to 15 μm. The pre-pressing pressure in step (1) is 20 to 40T; The vacuum hot pressing sintering in step (2) comprises: Vacuum to 10 -2 Pa, and then carry out one-stage hot pressing sintering, two-stage hot pressing sintering, three-stage hot pressing sintering and pressure treatment in sequence; The one-stage hot pressing sintering comprises: increasing the pressure at a first pressure increasing rate of 2 to 6 T / min, increasing the temperature to 500 to 600° C. at a first heating rate of 2 to 6° C. / min, stopping the pressure increasing and performing a first heat preservation and pressure holding for 1 to 3 hours; The two-stage hot pressing sintering includes: increasing the pressure at a second pressure increase rate of 0.5 to 3 T / min, increasing the temperature to 700 to 800° C. at a second temperature increase rate of 0.5 to 5° C. / min, and performing a second heat preservation for 1 to 2 hours; The three-stage hot pressing sintering includes: increasing the pressure at a third increasing pressure rate of 0.5 to 3T / min, increasing the temperature to 850 to 1000°C at a second increasing temperature rate of 0.5 to 5°C / min, stopping the pressure increase and performing a third heat preservation period of 150 to 240 minutes; The density of the powder metallurgy CrSi target material is 97-99%.

2. The preparation method according to claim 1, characterized in that: The purity of the Cr powder in step (1) is 99-99.9%.

3. The preparation method according to claim 1, characterized in that: The purity of the Si powder in step (1) is 99-99.9%.

4. The preparation method according to claim 1, characterized in that: The mixing in step (1) includes ball milling mixing.

5. The preparation method according to claim 1, characterized in that: The rotation speed of the ball milling mixing is 300-400 r / min.

6. The preparation method according to claim 1, characterized in that: The ball milling mixing time is 20 to 30 hours.

7. The preparation method according to claim 1, characterized in that: The material-to-ball ratio in the ball milling mixture is (8-12):

1.

8. The preparation method according to claim 1, characterized in that: The end point of the mold compaction in step (1) is: the mold flatness ≤ 1.0 mm.

9. The preparation method according to claim 1, characterized in that: The end point of the pressurization treatment: the pressure in the reaction furnace is -0.06MPa to -0.08MPa.

10. The preparation method according to claim 1, characterized in that: The post-processing in step (3) includes any one of grinding, wire cutting or polishing, or a combination of at least two of them.

11. The preparation method according to claim 1, characterized in that: The preparation method comprises the following steps: (1) Under a protective atmosphere, Cr powder with a purity of 99-99.9% and an average particle size of 50-80 μm and Si powder with a purity of 99-99.9% and an average particle size of 5-15 μm are mixed according to the formula, molded and compacted to a mold flatness of ≤0.1.0 mm, and then pre-pressed to a pressure of 20-40T to obtain a mixed powder; Wherein, the mixing includes ball milling mixing; the rotation speed of the ball milling mixing is 300-400 r / min, the time is 20-30 h, and the material-ball ratio is (8-12):1; (2) performing vacuum hot pressing sintering on the mixed powder obtained in step (1) to obtain a target material blank; Wherein, the vacuum hot pressing sintering comprises: vacuumizing to 10 -2 Pa, and then carry out one-stage hot pressing sintering, two-stage hot pressing sintering, three-stage hot pressing sintering and pressurizing treatment in sequence until the pressure in the reactor is -0.06MPa~-0.08MPa; The one-stage hot pressing sintering comprises: increasing the pressure at a first pressure increasing rate of 2 to 6 T / min, increasing the temperature to 500 to 600° C. at a first heating rate of 2 to 6° C. / min, stopping the pressure increasing and performing a first heat preservation and pressure holding for 1 to 3 hours; The two-stage hot pressing sintering includes: increasing the pressure at a second pressure increase rate of 0.5 to 3 T / min, increasing the temperature to 700 to 800° C. at a second temperature increase rate of 0.5 to 5° C. / min, and performing a second heat preservation for 1 to 2 hours; The three-stage hot pressing sintering includes: increasing the pressure at a third increasing pressure rate of 0.5 to 3T / min, increasing the temperature to 850 to 1000°C at a second increasing temperature rate of 0.5 to 5°C / min, stopping the pressure increase and performing a third heat preservation period of 150 to 240 minutes; (3) Cooling and post-processing the target material blank obtained in step (2) to obtain the powder metallurgy CrSi target material.

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