阅读说明：本技术 半导体晶面镀膜工艺 (Semiconductor crystal face coating process ) 是由 沈文齐 王文爽 于 2020-05-08 设计创作，主要内容包括：本发明公开一种半导体晶面镀膜工艺,包括以下步骤：S1：预处理：将半导体基片浸于清洗液中,45～60℃超声处理5～10min,洗涤、干燥；S2：等离子体沉积TiO<Sub>2</Sub>膜：将半导体基片置于射频等离子体装置内,抽真空至10<Sup>-2</Sup>～10<Sup>-1</Sup>Pa,通入氩气至气压为20～30Pa,放电3～5min,再以60～120sccm流量通入钛酸四乙酯蒸汽、氧气的混合气体,沉积8～12s,350～400℃热处理1～2h；S3：气相沉积MgF<Sub>2</Sub>膜：将半导体基片置于真空磁控溅射装置内,以金属镁作为靶材,抽真空至10<Sup>-4</Sup>～3×10<Sup>-3</Sup>Pa,设置靶材温度为200℃,溅射电流为10～13A,以100～500sccm流量通入SiF<Sub>4</Sub>、水蒸气、氩气的混合气体,溅射25～50nm。本发明克服对靶材自身特性的要求,实现在较低温度下镀制TiO<Sub>2</Sub>膜和MgF<Sub>2</Sub>膜,镀膜效率高,膜层结构稳定,厚度均匀,适合工业化批量生产。(The invention discloses a semiconductor crystal face coating process, which comprises the following steps: s1: pretreatment: immersing the semiconductor substrate in a cleaning solution, carrying out ultrasonic treatment at 45-60 ℃ for 5-10 min, washing and drying; s2: plasma deposition of TiO 2 Film formation: placing the semiconductor substrate in a radio frequency plasma device, and vacuumizing to 10 DEG ‑2 ～10 ‑1 Pa, introducing argon gas until the pressure is 20-30PDischarging for 3-5 min, introducing mixed gas of tetraethyl titanate steam and oxygen at the flow rate of 60-120 sccm, depositing for 8-12 s, and performing heat treatment at 350-400 ℃ for 1-2 h; s3: vapor deposition of MgF 2 Film formation: placing a semiconductor substrate in a vacuum magnetron sputtering device, taking metal magnesium as a target material, and vacuumizing to 10 DEG ‑4 ～3×10 ‑3 Pa, setting the target material temperature at 200 ℃, sputtering current at 10-13A, and introducing SiF at the flow rate of 100-500 sccm 4 Sputtering the mixed gas of water vapor and argon gas for 25-50 nm. The invention overcomes the requirement on the self characteristics of the target material and realizes the TiO plating at lower temperature 2 Film and MgF 2 The film has high film coating efficiency, stable film structure and uniform thickness, and is suitable for industrial batch production.)

1. A semiconductor crystal face coating process is characterized by comprising the following steps:

s1: pretreatment: soaking the semiconductor substrate in a cleaning solution, carrying out ultrasonic treatment at 45-60 ℃ for 5-10 min, removing surface oil stains and impurities, washing with clean water for 3-4 times, and drying;

s2: plasma deposition of TiO₂Film formation: placing the pretreated semiconductor substrate in a radio frequency plasma device, and vacuumizing to 10 DEG^-2～10^-1Introducing argon to the pressure of 20-30 Pa, discharging at the power of 50-70W for 3-5 min, introducing mixed gas of tetraethyl titanate steam and oxygen at the flow of 60-120 sccm, depositing for 8-12 s, and then performing heat treatment at 350-400 ℃ for 1-2 h;

s3: vapor deposition of MgF₂Film formation: placing the pre-coated semiconductor substrate in a vacuum magnetron sputtering device, taking magnesium metal as a target material, and vacuumizing to 10 DEG^-4～3×10^-3Pa, setting the target material temperature at 200 ℃, sputtering current at 10-13A, and introducing SiF at the flow rate of 100-500 sccm₄Sputtering the mixed gas of water vapor and argon gas for 25-50 nm.

2. The process of claim 1, wherein the semiconductor substrate is made of one of a silicon single crystal, a silicon carbide single crystal and a germanium single crystal.

3. The semiconductor crystal face coating process according to claim 1, wherein the cleaning solution comprises the following components in percentage by mass: 2.5-5% of sulfamic acid, 1-3% of hydrofluoric acid, 3-6% of polyaspartic acid, 1-2% of polyoxyethylene fatty acid ester and the balance of water.

4. The process for coating a semiconductor crystal face according to claim 1, wherein the volume ratio of the tetraethyl titanate vapor to the oxygen is 1: (1.2-2.4).

5. The process of claim 1, wherein the SiF is deposited on the substrate₄The volume ratio of the water vapor to the argon is 1: (3-4): (40-65).

Technical Field

The invention belongs to the technical field of semiconductor processing, and particularly relates to a semiconductor crystal face coating process.

Background

The semiconductor refers to a material with electric conductivity between a conductor and an insulator at normal temperature, and is applied to the fields of integrated circuits, consumer electronics, communication systems, photovoltaic power generation, illumination application, high-power conversion and the like. Common semiconductor materials include silicon, germanium, gallium arsenide, and the like, wherein silicon single crystals and germanium single crystals are mainly applied to the optical field, such as solar cells, infrared optical lenses, windows, and the like. In order to improve the optical performance of semiconductors, increase the light conversion efficiency, and reduce the light reflection, one or more optical thin films are generally coated on the surface of a semiconductor crystal such as silicon or germanium. At present, the semiconductor coating method mainly comprises an evaporation coating method, a sputtering coating method and a chemical vapor deposition method, wherein the evaporation coating is not suitable for materials with high melting points, the materials with high melting points have high energy consumption and slow evaporation, the sputtering coating is not suitable for materials with low hardness and insulating materials, and the direct current sputtering requires that a target material can transfer positive charges obtained in the ion bombardment process to a cathode which is in close contact with the target material, so that the method can only sputter conductor materials, is not suitable for insulating materials, and has poor conductivity for most non-metal materials.

Based on the above, the invention provides a novel method for plating a titanium oxide protective film and a magnesium fluoride antireflection film on a semiconductor crystal face with high efficiency.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to provide a semiconductor crystal face coating process.

The technical scheme of the invention is summarized as follows:

a semiconductor crystal face coating process comprises the following steps:

s1: pretreatment: soaking the semiconductor substrate in a cleaning solution, carrying out ultrasonic treatment at 45-60 ℃ for 5-10 min, removing surface oil stains and impurities, washing with clean water for 3-4 times, and drying;

s2: plasma deposition of TiO₂Film formation: placing the pretreated semiconductor substrate in a radio frequency plasma device, and vacuumizing to 10 DEG^-2～10^-1Introducing argon to the pressure of 20-30 Pa, discharging at the power of 50-70W for 3-5 min, introducing mixed gas of tetraethyl titanate steam and oxygen at the flow of 60-120 sccm, depositing for 8-12 s, and then performing heat treatment at 350-400 ℃ for 1-2 h;

s3: vapor deposition of MgF₂Film formation: placing the pre-coated semiconductor substrate in a vacuum magnetron sputtering device, taking magnesium metal as a target material, and vacuumizing to 10 DEG^-4～3×10^-3Pa, setting the target material temperature at 200 ℃, sputtering current at 10-13A, and introducing SiF at the flow rate of 100-500 sccm₄Sputtering the mixed gas of water vapor and argon gas for 25-50 nm.

Preferably, the semiconductor substrate material is one of a silicon single crystal, a silicon carbide single crystal, and a germanium single crystal.

Preferably, the cleaning solution comprises the following components in percentage by mass: 2.5-5% of sulfamic acid, 1-3% of hydrofluoric acid, 3-6% of polyaspartic acid, 1-2% of polyoxyethylene fatty acid ester and the balance of water.

Preferably, the volume ratio of the tetraethyl titanate steam to the oxygen is 1: (1.2-2.4).

Preferably, the SiF₄The volume ratio of the water vapor to the argon is 1: (3-4): (40-65).

The invention has the beneficial effects that:

1. the invention removes the stains and the passive film on the surface of the semiconductor by using the cleaning solution in advance and then uses the radio frequency plasma to deposit TiO by vapor phase deposition₂Film to form a protective film on the semiconductor to prevent MgF deposition₂Chemical corrosion of the semiconductor crystal face occurs during the film process, and at the same time, TiO₂Has excellent photocatalytic property, improves the antifouling and self-cleaning performance of the semiconductor, and finally combines a direct current magnetron sputtering method and a vapor deposition method to plate MgF₂Film for effectively reducing light reflection and improving photoelectric conversion efficiency of semiconductorAnd properties.

2. Compared with the traditional evaporation and sputtering process, the invention overcomes the requirement on the characteristics of the target material and realizes the TiO plating at lower temperature₂Film and MgF₂The film has high film coating efficiency, compact and stable film structure and uniform thickness, and is suitable for industrial batch production.

Drawings

FIG. 1 is a flow chart of a process for coating a film by using a semiconductor crystal surface according to the present invention.

Detailed Description

The present invention is further described in detail below with reference to examples so that those skilled in the art can practice the invention with reference to the description.