Semiconductors undergo many processes to become functional for the various applications they are utilized in. Sputtering is a process that is used in many industries, but what exactly is it and why is it used?
In particular, semiconductor sputtering is a process that is used to deposit thin films of material onto a substrate. There are several reasons why this process might be used in the semiconductor industry, including creating device contacts, forming resistors and capacitors, and manufacturing transistors. Let’s take a closer look at semiconductor sputtering and find out why it’s such an important part of the semiconductor fabrication process.
What Is Sputtering?
Sputtering is the process of ejecting surface atoms of a solid target material that shift from their solid phase to their gas phase after it has been bombarded with energetic ions. The kinetic energy of the incident ions must be higher than the target surface binding energy for sputtering to take place. This is a physical vapor deposition method that renders a thin film and coating on the sputtering target material or ‘substrate’, most often inside a vacuum chamber. The average quantity of target atoms that leave the surface for each incident ion is known as the sputter yield.
In layman’s terms, this process involves a material being bombarded by particles containing energy in the form of plasma or inert gas. This moment of collision results in particles being ejected from the surface of the solid material that was bombarded. The conventional thermal energies should be less than that of the ion bombardment that acts upon it. This procedure usually takes place in outer space on its own accord but we humans have used it in various applications down here too.
There are many different types of sputtering, from DC sputtering using a direct current to magnetron sputtering, reactive sputtering, RF sputtering, and more. The ability to carry out sputtering on thin film materials has helped in the fabrication of many devices and equipment ranging from nanotechnology materials to optical material coatings, semiconductor devices, and more.
We’ll look into the details of sputtering in the semiconductor scope right below, from how the process is carried out to its importance and drawbacks
The Sputtering Process In The Semiconductor Industry
In the semiconductor industry, sputtering target materials are required for many procedures of the semiconductor manufacturing process. This includes the wafer fabrication process dealing with the wafer conductive layer, barrier layer, and more. The sputtering process is also used in the semiconductor chip packing process.
The main methods of sputtering used are ion beam sputtering for sputter etching in semiconductors and reactive sputtering. But, why is sputtering so important for semiconductors?
The Importance Of Sputtering Targets For Semiconductors
Technological advances and growing consumer demands for more lightweight devices requiring less power and better processing means that the sputtering techniques and targets used in the fabrication of semiconductors must help improve these factors.
Sputtering is used in both wafer fabrication and chip packaging as mentioned above. However, semiconductors are very sensitive devices and require high purity for both water and chip production due to how easily particles form on their surfaces. To meet consumer demands, this means that the quality of the sputtering target material must be at its best, which is usually 99.9995% (5N5) or higher.
The effectiveness of the sputtering process directly correlates to the quality of metal target materials. High quality affects many aspects of semiconductor fabrication, as the purity of the sputtering target materials will directly show in the uniformity and conductive capabilities of the conduction layer and barrier layer. Consequently, this also affects the momentum transfer and stability of chip transmission.
There are many different types of sputtering target materials and evaporation materials used in semiconductor fabrication, which we will discuss in detail below.
Sputtering Target Materials For Semiconductors
Various elements can be used as sputtering target materials to be bombarded with different forms of high-energy particles. These elements have different levels of purity and different forms like monoblocks and compounds of varying sizes. They also differ in the cathode materials they utilize for the process and undergo different mounting methods. Each sputtering target differs in its use case and is only suitable for a specific sputtering target system with particular coating materials.
Below are most of these elements, but note that they are not functional across all applications.
- Gold (2805 g), (5605 g)
- Palladium (1745 g), (3490 g)
The Drawbacks Of Semiconductor Sputtering/Etching
Sputtering has many advantages but not without a few drawbacks. This physical process needs the best sputtering equipment and high-purity target materials to ensure the silicon wafer or other wafer material does not get damaged quickly.
If the sputtering process does not happen under controlled conditions and with high-purity sputtering targets, it will easily cause a film on the wafer. This will lead to short circuits or irrecoverable circuit damage.
High Voltage Use
This process requires high ion energy and it can be quite an exhausting process to arrange and carry out.
High-Quality Semiconductor Components For Your Devices
Sputtering and etching are key processes for the fabrication of semiconductor devices. In this article, we’ve looked at what sputtering is and how it works in the semiconductor industry. We’ve also seen that sputter deposition is an important step in fabricating high-quality semiconductors and that sputter etching makes these devices more efficient. While there are some drawbacks to using sputtering technology – wafer damage and high voltage use – the benefits of faster, better quality products outweigh these concerns.
At Inquivix Technologies, we distribute high-quality semiconductor manufacturing equipment sourced from trusted manufacturers across South Korea. Contact us to learn more about our products and services.
Sputtering is widely used in the field of semiconductor manufacturing, to form thin layers of different materials as part of integrated circuit processing. Additionally, this technology can be leveraged to deposit optical antireflection coatings on glass for numerous applications.
RF magnetron sputtering is a superior method compared to DC magnetron sputtering because it doesn’t require an electrically conductive target. This allows any material, in theory, to be sputter-deposited using this revolutionary technique.