What Is Etching Equipment?
Etching equipment is used in the etching process of semiconductor manufacturing.
The etching process is a technology that cuts or dissolves the surface of the processed object. Etching equipment performs etching processes on thin films and other materials formed on semiconductor wafers and is indispensable for the manufacture of CPUs and other electronic devices.
As electronic devices have become more sophisticated in recent years, etching is required to achieve finer and finer processing. The process has also become more complex, and multiple etching equipment is often used to manufacture a single electronic component.
Uses of Etching Equipment
Etching equipment is indispensable for the manufacture of electronic devices. Specific applications are as follows:
- Integrated circuits such as CPUs for PCs
- Printed circuit boards
- Liquid crystal display panels
- Plasma display panels
Photolithography, used in the manufacture of these products, is a technology that processes the surface of an object by applying light on top of an applied photosensitive material. One of the processes of photolithography is etching.
In the etching process, areas of the oxide film on the wafer that is coated with resist remain, while areas that are not coated with resist peel off. Unevenness is created and a pattern is formed.
Principle of Etching Equipment
Etching equipment is classified into two types: wet etching and dry etching.
1. Wet Etching
Wet etching is a process that dissolves oxide film using acid or alkaline chemical solutions. A large number of sheets can be processed at one time, and production quality is stable.
Since the chemical solution is relatively inexpensive, it can be manufactured at a low cost. However, since etching proceeds in one direction, vertical processing is not possible (1 μm is the limit).
2. Dry Etching
Dry etching is an etching process that does not use chemicals. Plasma etching is the most widely used dry etching method. Plasma etching is a method in which gas is plasmaized under a vacuum with high voltage.
There are two types of plasma etching methods, dielectric coupling type, and microwave type, both of which use a high-frequency power supply. This method uses the generated plasma to scrape the surface of the object and is more expensive than wet etching. However, it is possible to process grooves as fine as 100 nm to 1,000 nm.
Other types of plasma etching include ion etching by ion impact and gas etching that uses gas, both of which require vacuum equipment.
Other Information on Etching Equipment
1. Etching Equipment Market and Share
The global electronics market continues to expand, and the semiconductor industry, which supports this expansion, is becoming increasingly important. The global market for semiconductors is expanding despite experiencing recessions such as the Lehman Shock.
In recent years, the development of technologies to further miniaturize storage media by using a 3D structure is flourishing. Therefore, etching equipment is becoming even more important as a core technology for 3D.
The etching equipment consumption market size was 1,389.3 billion yen in 2018. The market shares by consumption region are South Korea (28%), China (19%), Japan (19%), Taiwan (14%), and the United States (10%). Also, vendor share by nationality in 2018 was the U.S. (64%) and Japan (32%), As of 2018, the U.S. and Japanese companies oligopoly in the market.
2. Dry Etching Equipment and 3D NAND Market
Dry etching is one of the microfabrication technologies, and many types of etching equipment are available depending on the material to be processed. However, equipment mainly targeting semiconductors and metals, such as silicon and metal wiring, is the mainstream. Insulating film dry etching equipment accounts for a high percentage of the equipment used in normal semiconductor plants.
In 2017, the dry etching equipment market was worth US$10.7 billion.
The rapid growth of the dry etching equipment market is attributed to the increasing three-dimensional structure of memory. As miniaturization progresses, dry etching processes increase and flash memory has developed a three-dimensional structure.
Various processes are required to form the cells of 3D NAND flash memory. In particular, deep channel hole processing is difficult and requires a long etching process. In semiconductor memory factories, the number of pieces processed per hour is critical. Therefore, the number of dry etching equipment installed is increased to ensure processing capacity.