4 Types of Wet Cleaning Method of Silicon Wafer

After the silicon wafer is processed by different processes such as slicing, chamfering, grinding, surface treatment, polishing, and epitaxy, the surface has been seriously stained. The purpose of cleaning is to remove particles, metal ions and organic substances on the surface of the silicon wafer.

Wet cleaning uses chemical solvents with strong corrosive and oxidizing properties, such as H2SO4, H2O2, DHF, NH3•H2O, etc. The impurity particles on the surface of the silicon wafer react with the solvent to form soluble substances and gases. In order to improve the cleaning effect, it is possible to use mega-acoustic, heating, vacuum and other technical means, and finally use ultra-pure water to clean the surface of the silicon wafer to obtain a silicon wafer that meets the cleanliness requirements.

There are several methods for wet cleaning:

RCA cleaning

Kern et al. proposed the RCA cleaning method in 1965. According to the SPM, DHF, SC-1, and SC-2 sequences, the RCA cleaning method basically satisfies the requirements of most wafer cleanliness. Cleaning the silicon wafer by this method not only improves the cleaning efficiency, reduces the cost, saves time, obtains excellent surface cleanliness, but also improves the electrochemical performance of the silicon wafer.

Ultrasonic cleaning

Ultrasonic cleaning is a cleaning method widely used in the semiconductor industry. The method has the advantages of good cleaning effect, simple operation, and can be removed for complicated devices and containers; but the method also has the disadvantages of high noise and easy breakage of the transducer.

This method can effectively remove organic, particulate, and metal ion impurities on the surface of the silicon wafer by utilizing the mechanical action of high-frequency sound waves, the cavitation effect of the solution, and the complexation reaction of chemical reagents. Using a similar method, BongKyun et al. used a 0.83 MHz megasonic wave to clean the silicon wafer, which is more excellent and can remove particulate impurities below 0.3 μm.

silicon wafer wet cleaning

Double flow spray

The dual-flow atomizing nozzle cleans the silicon wafer by using a nozzle to scan the silicon wafer back and forth with the rotating arm, and the silicon wafer rotates clockwise. The dual-flow nozzle uses a high-pressure, high-speed jet of gas to impinge a vulgar flow of liquid, destroying the surface tension of the liquid and the van der Waals bond and hydrogen bond between the liquid molecules, causing the liquid to atomize and become nanometer-sized droplets, which are ejected at high speed through the nozzle under the action of high pressure air.

Ozone microbubble method

The high activity and strong oxidizing properties of ozone can remove organic and particulate impurities on the surface of the silicon wafer. Ozone is dissolved in water to form a highly reactive OH group, and the OH group chemically reacts with the organic substance to remove organic impurities on the surface of the silicon wafer. At the same time, the surface of the silicon product is covered with an atomic-level smooth oxide film, which effectively isolates the re-adsorption of impurities.

This method has excellent cleaning effect, basically removes organic and particulate impurities, and meets the requirements of general silicon wafer cleanliness. At the same time, ozone microbubble cleaning produces less polluting waste and high cleaning efficiency, and can be used for cleaning large-scale circuits, silicon wafers and LEDs.

For more information, please visit https://www.sputtertargets.net/.

A short analysis of sputtering targets for semiconductor application

Semiconductors have high requirements for the quality and purity of the sputtering materials, which explains why the price of anelva  targets is relatively high.

Undoubtedly, sputtering targets are the most important raw materials in current semiconductor manufacturing processes. Their quality and purity play a key role in the subsequent production quality of the semiconductor industry chain. And anelva targets refer to those sputtering targets used in the semiconductor industry.

Application requirements

Semiconductors have high requirements for the quality and purity of the sputtering materials, which explains why the price of anelva  targets is relatively high. In the semiconductor manufacturing process, if the impurity content of the sputtering target is too high, the formed film cannot achieve the required electrical properties, and it is liable to cause short circuit or damage of the circuit, which will seriously affect the performance of the film.

Therefore, when purchasing semiconductor targets, be sure to find a reliable sputtering targets manufacturers for high-quality & high-purity sputtering targets.

blue computer circuit board closeup , semiconductor industry

Market Size

With the rapid development of terminal applications such as consumer electronics, the market sales of high-purity sputtering targets are expanding.

According to statistics, in 2015, the global high-purity sputtering target market sales reached 9.48 billion US dollars, of which, the semiconductor sputtering target market sales of 1.14 billion US dollars. It is estimated that in the next five years, the market size of the world’s sputtering targets will exceed 16 billion US dollars, and the CAGR (Compound Annual Growth rate) of the high-purity sputtering target market will reach 13%.

According to statistics from WSTS (World Semiconductor Trade Statistics), the global target market is expected to grow at the same rate as 2017 (13%). In 2016, the global sputtering target market capacity was US$11.36 billion, an increase of 20% compared to US$9.48 billion in 2015. It can be inferred that the market size of the global high-purity sputtering target in 2018 is about 14.5 billion US dollars.

Stanford Advanced Materials (SAM) Corporation is a global supplier of sputtering targets such as metals, alloys, oxides and ceramic materials, which are widely used in multiple industries. Please visit https://www.sputtertargets.net/ for more information.

Semiconductor industry: The importance of Anelva target

The sputtering target materials can be divided into metal target (pure metal gold, aluminumtitanium, etc.), alloy target (aluminum-scandium alloy, cobalt-aluminum alloy, aluminum-titanium alloy, etc.) and ceramic compound target (oxides, nitride, silicides, etc.) according to their different chemical compositions; when it comes to different application fields, it can be categorized into semiconductor target, planar display target, solar cell target, and other target materials. Anelva target refers to the sputtering target used in semiconductor industry.

Although the proportion of Anelva target is just about 3% among all the sputtering targets, it cannot be denied that its application in semiconductor chip market is important and irreplaceable. There are generally two kinds of Anelva target: wafer materials and packaging materials. Today we mainly focus on wafer manufacturing materials because they have relatively high technical barriers than the other.

The inner part of the semiconductor is composed of tens of thousands of meters of metal wiring, and the sputtering target material is the key consumption material for making these wiring. In other words, the Anelva target is the core of semiconductor wafer manufacturing. Since the chip is elaborate, it has high requirements for sputtering target material used in the manufacturing process. Generally, the purity of the target material is over 99.999%.

Semiconductor wafers are the basic material for manufacturing chips (as shown below). It is small but complicated. The production of wafer mainly involves 7 kinds of semiconductor materials and chemicals. The most important raw material for semiconductor integrated circuits is silicon, which is widely found in rocks and gravel in the form of silicate or silicon dioxide in nature. The manufacturing process of silicon wafers can be divided into three basic steps: silicon purification, monocrystalline silicon growth, and wafer formation. Apart from silicon, the manufacturing process of 200mm (8-inch) and below wafers is usually mainly made of aluminum, and the manufacture of 300mm (12-inch) wafer mostly uses advanced copper interconnection technology.

Semiconductor wafer

In conclusion, with more extensive use of semiconductor chips, the demand for aluminum, titanium, tantalum and copper, the four mainstream Anelva target, will also increase. There is currently no alternative to these target materials, either technically or economically, so, as I mentioned before,  they are important and irreplaceable.

Please visit https://www.sputtertargets.net/ for more information.

How is tantalum used in phones?

We have talked about the Application of Tantalum Target in Thermal Inkjet Print Head and Copper Plating before, which rises your interest on this element. However, most people think thermal inkjet print and copper plating are far away from their life, thus are difficult to understand. So today, SAM sputter targets will talk about something that EVERYONE is familiar with—your mobile phones.

tantalum

Tantalum is a very important element in the electronic industry. And it is widely used in all kinds of electronic devices, such as phones and computers. The main use of tantalum materials in electronic products comes in the creation of tantalum capacitor. Tantalum capacitors have their unique advantages over other capacitors. They do not use electrolytes like ordinary electrolytic capacitors, making them ideal for operation at high temperatures. Solid tantalum capacitors have excellent electronic properties, wide operating temperature range, various forms and excellent volumetric efficiency.

Continue reading “How is tantalum used in phones?”

Manufacturing process of semiconductor wafer

Semiconductor wafers are the basic material for manufacturing chips. The most important raw material for semiconductor integrated circuits is silicon, which is widely found in rocks and gravel in the form of silicate or silicon dioxide in nature. The manufacturing process of semiconductor wafers/silicon wafers can be divided into three basic steps: silicon purification, monocrystalline silicon growth, and wafer formation.

Silicon purification

The sandstone material is placed in a 2000 °C electric arc furnace which has a carbon source. At high temperatures, the silica in the carbon and in the sandstone undergoes a chemical reaction (carbon is combined with oxygen, leaving silicon) to obtain pure silicon having a purity of about 98%, also known as metallurgical grade silicon. Continue reading “Manufacturing process of semiconductor wafer”