阅读说明：本技术 一种铋电镀液及电镀制备铋薄膜的方法 (Bismuth electroplating solution and method for preparing bismuth film by electroplating ) 是由 陈建 王雪深 李劲劲 徐骁龙 于 2021-06-17 设计创作，主要内容包括：本发明公开了一种铋电镀液及电镀制备铋薄膜的制备方法,包括导电盐0.5-2.0mol/L、硝酸0.5-3.0mol/L、甘油0.50-3.0mol/L、络合剂0.20-1.0mol/L、五水硝酸铋0.05-0.50mol/L。本发明采用无氰镀液配制、性能稳定,绿色环保,电镀工艺容易操作,通过调控脉冲参数和镀液成分及浓度,可对镀铋薄膜进行控制,制备出表面平滑光亮、孔隙率低、结合力好,厚度易控等特点的铋薄膜。(The invention discloses a bismuth electroplating solution and a preparation method for preparing a bismuth film by electroplating, which comprises 0.5-2.0mol/L of conductive salt, 0.5-3.0mol/L of nitric acid, 0.50-3.0mol/L of glycerol, 0.20-1.0mol/L of complexing agent and 0.05-0.50mol/L of bismuth nitrate pentahydrate. The method adopts cyanide-free plating solution for preparation, has stable performance, is green and environment-friendly, is easy to operate in electroplating process, can control the bismuth-plated film by regulating and controlling pulse parameters and plating solution components and concentration, and prepares the bismuth film with the characteristics of smooth and bright surface, low porosity, good bonding force, easy thickness control and the like.)

1. A bismuth electroplating solution is characterized in that: comprises 0.5-2.0mol/L of conductive salt, 0.5-3.0mol/L of nitric acid, 0.50-3.0mol/L of glycerol, 0.20-1.0mol/L of complexing agent and 0.05-0.50mol/L of bismuth nitrate pentahydrate.

2. The plating solution as set forth in claim 1, wherein: the conductive salt is at least one of potassium hydroxide, potassium nitrate or potassium chloride.

3. The plating solution as set forth in claim 1, wherein: the complexing agent is at least one of L-tartaric acid, potassium citrate and triethanolamine.

4. A method for preparing a bismuth film by electroplating comprises the steps of placing a silicon wafer in electroplating solution to be used as a cathode, placing titanium platinum in the electroplating solution to be used as an anode, and then switching on a direct current power supply, wherein the electroplating solution is used for preparing the bismuth film by the electroplating solution of any one of claims 1 to 3, and the bismuth film is prepared by electroplating by taking the silicon wafer with a cathode seed layer deposited as the cathode and titanium platinum as the anode.

5. The method for preparing the bismuth film by electroplating according to claim 4, wherein the preparation method of the cathode seed layer comprises the steps of depositing 3-20nm of Ti on a silicon wafer and then depositing 20-200nm of Au to prepare the silicon wafer on which the cathode seed layer is deposited.

6. The method for preparing bismuth film by electroplating according to claim 4, wherein the current density is 0.5-20mA/cm²The temperature of the electroplating solution is 20-70 ℃, and the pH value is 0-1.0.

7. The method for preparing the bismuth film by electroplating according to claim 4, wherein the electroplating mode adopts a pulse method or a constant current method for electroplating.

8. The method for preparing the bismuth film by electroplating according to claim 4, wherein the cathode is separated from the anode by a distance of 5-15 cm.

Technical Field

The invention belongs to the technical field of electroplating, and particularly relates to a bismuth electroplating solution and a preparation method for preparing a bismuth film through electroplating.

Background

Bismuth is an orthorhombic metal in a transition state, has covalent bonds and metal bonds, has a series of special physical and chemical properties due to the structure, and is widely applied to the fields of semiconductors, superconducting materials, electroplating, batteries and the like. Bismuth has oxidation resistance under dry and wet conditions at normal temperature, has better stopping capability to X-rays, and has higher sensitivity and conductivity to heat, so that bismuth is commonly used for preparing the material of the TES absorber for X-rays. In recent years, with the development of bismuth industry and the attention of people on environmental protection, the trend of green, environmental protection and lead-free processing provides good development prospect for deep processing of bismuth series products. Therefore, the research and preparation of the bismuth film has important significance for the development and application of 'green metal' bismuth and the research of new materials.

The electroplating solution comprises cyanide-containing plating solution and cyanide-free plating solution, wherein the cyanide-containing electroplating solution is stable and reliable, has high current efficiency and good dispersing capacity and covering capacity, and the obtained plating layer has fine and bright crystals and is generally adopted by countries in the world; however, cyanide has high toxicity, so that many problems exist in the aspects of working environment and waste liquid treatment, and particularly, the cyanide-free electroplating technology with low toxicity is gradually paid high attention from various countries in the world along with the improvement of environmental awareness, so that the research and popularization of the cyanide-free plating solution system are imperative. Therefore, a bismuth electroplating solution and a preparation method for preparing a bismuth film by electroplating are provided.

Disclosure of Invention

The invention aims to solve the problems in the prior art and provides a bismuth electroplating solution and a preparation method for preparing a bismuth film by electroplating.

In order to achieve the purpose, the invention adopts the following technical scheme:

the invention comprises 0.5-2.0mol/L of conductive salt, 0.5-3.0mol/L of nitric acid, 0.50-3.0mol/L of glycerol, 0.20-1.0mol/L of complexing agent and 0.05-0.50mol/L of bismuth nitrate pentahydrate.

Further, the conductive salt is at least one of potassium hydroxide, potassium nitrate or potassium chloride.

Further, the complexing agent is at least one of L-tartaric acid, potassium citrate and triethanolamine.

A method for preparing a bismuth film by electroplating comprises the steps of placing a silicon wafer in electroplating solution to serve as a cathode, placing titanium platinum in the electroplating solution to serve as an anode, then switching on a direct current power supply, using the electroplating solution as the electroplating solution to prepare the bismuth film, and electroplating by using the silicon wafer deposited with a cathode seed layer as the cathode and the titanium platinum as the anode to prepare the bismuth film.

Further, the preparation method of the cathode seed layer comprises the steps of depositing 3-20nm Ti on the silicon wafer and then depositing 20-200nm Au to prepare the silicon wafer with the cathode seed layer deposited.

Further, it is characterized in that the current density is 0.5 to 20mA/cm²The temperature of the electroplating solution is 20-70 ℃, and the pH value is 0-1.0.

Furthermore, the electroplating mode adopts a pulse method or a constant current method for electroplating.

Further, the spacing distance between the cathode and the anode is 5-15 cm.

Compared with the prior art, the invention has the beneficial effects that:

compared with the prior art, the bismuth plating electroplating solution has the advantages of good stability, long service life, high dispersing and covering capacities and high conductivity, and can be used for preparing a bismuth film material with a compact and flat surface, low porosity, high binding force and a film thickness of hundreds of nanometers to dozens of micrometers.

Drawings

FIG. 1 is a schematic diagram showing the comparison of XRD data of a bismuth film obtained by electroplating the bismuth film prepared by the bismuth electroplating solution and electroplating with the bismuth film of the present invention with a bismuth standard card;

FIG. 2 is a schematic diagram of the bismuth electroplating solution and the electroplating process for preparing a bismuth film by electroplating according to the present invention;

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments.

In this example 1, the plating of a bismuth thin film using the above-mentioned plating solution comprises the following steps

Preparing electroplating solution; the prepared bismuth plating electroplating solution comprises the following reagent components: 0.5mol/L of potassium hydroxide or potassium nitrate or potassium chloride, 2.0mol/L of nitric acid, 1.5mol/L, L mol/L of glycerin-tartaric acid, 0.3mol/L of bismuth nitrate pentahydrate and the balance of deionized water.

Preparation process of electroplating

Preparing a cathode seed layer: firstly depositing 5nm Ti on a silicon wafer, and then continuously depositing 80nm Au to prepare an electroplating seed layer;

and transferring the electroplating solution into an electroplating bath, wherein the silicon wafer for depositing the seed layer is taken as a cathode, the titanium platinum is taken as an anode, and the spacing distance between the cathode and the anode is 5-15 cm. The power supply for electroplating is a single-pulse electroplating power supply, electroplating is carried out, and a film deposited on the surface of the cathode seed layer is the prepared bismuth film; and washing the bismuth film-plated silicon wafer by deionized water, and drying on a hot plate to obtain a finished bismuth film.

The electroplating process condition is that the current density is 0.5mA/cm²The temperature of the electroplating solution is 30 ℃, the pH value is 0.6, the electroplating time is set, the electroplating mode adopts a pulse method or a constant current method and the like for electroplating, and the electroplating process is started.

The thickness of the obtained film is 60nm (electroplating time is 2min), and the grain size is about 100 nm.

In this example 2, the following reagent components were included: 1.0mol/L of potassium hydroxide, 1.0mol/L of nitric acid, 0.9mol/L, L-tartaric acid, 0.30mol/L of bismuth nitrate pentahydrate and the balance of deionized water;

preparing a cathode seed layer: after 9nm Ti is firstly deposited on the silicon wafer, 100nm Au is continuously deposited to prepare an electroplating seed layer, and the spacing distance between a cathode and an anode is 10 cm. The electroplating process condition is that the current density is 0.7mA/cm²The temperature of the plating solution was 40 ℃ and the pH was 0.3, as in example 1.

The obtained film has a thickness of 100nm (electroplating time of 2min) and a grain size of about 200nm

In this example 3, the following reagent components were included: 2.0mol/L potassium hydroxide, 3.0mol/L nitric acid, 2.0mol/L, L-tartaric acid, 0.50mol/L bismuth nitrate pentahydrate, and the balance of deionized water;

preparing a cathode seed layer: after 10nm Ti is firstly deposited on a silicon wafer, 200nm Au is continuously deposited to prepare an electroplating seed layer, and the spacing distance between a cathode and an anode is 15 cm. The electroplating process condition is that the current density is 10mA/cm²The temperature of the plating solution was 40 ℃ and the pH was 0.3, as in example 1.

The obtained film has a thickness of 780nm (electroplating time of 2min) and a grain size of about 900nm

The data of the embodiment examples 1-3 show that, as shown in fig. 1 and 2, the bismuth plating solution has good stability, long service life, high dispersion and covering power, strong conductivity, and can be used to prepare bismuth thin film materials with compact and flat surface, low porosity, good bonding force, and film thickness of several hundred nm to several tens of μm. The method adopts cyanide-free plating solution for preparation, has stable performance, is green and environment-friendly, is easy to operate in electroplating process, can control the bismuth-plated film by regulating and controlling pulse parameters and plating solution components and concentration, and prepares the bismuth film with the characteristics of smooth and bright surface, low porosity, good bonding force, easy thickness control and the like.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be considered to be within the technical scope of the present invention, and the technical solutions and the inventive concepts thereof according to the present invention should be equivalent or changed within the scope of the present invention.