Photoresist Overview
Photoresist Overview – Photoresist Spray Coating – Cheersonic
Photoresist is one of the eight core materials of semiconductors. According to the latest data, photoresist accounts for 5% of the value of semiconductor wafer manufacturing materials, photoresist auxiliary materials account for 7%, and the two together account for 12%. Adhesives and auxiliary materials are the fourth largest semiconductor materials after silicon wafers, electronic gases and photomasks. This article mainly introduces the photoresist, the core material of semiconductor, and its industrial situation.
1. Definition and main components of photoresist
Photoresist, also known as photoresist, refers to a resist etching film material whose solubility changes through ultraviolet light, electron beam, ion beam, X-ray, etc. irradiation or radiation. It is currently widely used in the optoelectronic information industry. The micro-pattern circuit processing and production link. Photoresist is composed of sensitizer (photoinitiator), photosensitive resin (polymerization agent), solvent and auxiliary agent.
1) Sensitizer (photoinitiator): It is the key component of photoresist and plays a decisive role in the sensitivity and resolution of photoresist.
2) Photosensitive resin (polymerizing agent): It is used to polymerize different materials in the photoresist to form the skeleton of the photoresist, which determines the basic properties of the photoresist such as hardness, flexibility, and adhesion.
3) Solvent: It is the largest component in the photoresist. The purpose is to keep the photoresist in a liquid state, but the solvent itself has almost no effect on the chemical properties of the photoresist.
4) Additives: Usually proprietary compounds, mainly used to change the specific chemical properties of the photoresist.
2. Main classification of photoresist
According to the application field, photoresist can be divided into semiconductor photoresist, LCD photoresist and PCB photoresist, and the technical barriers are decreased in turn (semiconductor photoresist > LCD photoresist > PCB photoresist).
3. Overview of the photoresist industry chain
Upstream of the industrial chain: mainly involves raw material suppliers such as solvents, resins, photosensitizers, and equipment suppliers such as lithography machines, developing machines, and testing and testing.
Midstream of the industry chain: It is the photoresist manufacturing link.
Downstream of the industrial chain: mainly involving semiconductors, flat panel displays, PCBs and other fields. With the acceleration of consumption upgrades and the accelerated iteration of application terminal products, downstream application companies have put forward more and more refined requirements for semiconductor, flat panel display and PCB manufacturing, which will drive the sustainable development of the photoresist industry.
4. Semiconductor lithography process flow
The lithography process goes through such processes as dehydration baking, spin coating, soft baking, exposure, post-exposure baking, development, hard film baking, and development inspection. In the photolithography process, the photoresist is uniformly coated on the substrate. After exposure, development and etching, the pattern on the mask is transferred to the substrate to form a geometry that completely corresponds to the mask. graphics. The lithography process accounts for about 35% of the entire chip manufacturing cost, and the time-consuming process accounts for 40-50% of the entire chip process. It is the most core process in semiconductor manufacturing.
Ultrasonic spraying technology is used for semiconductor photoresist coating. Compared with traditional coating processes such as spin coating and dip coating, it has the advantages of high uniformity, good encapsulation of microstructures, and controllable coating area. In the past 10 years, it has been fully demonstrated that the 3D microstructure surface photoresist coating using ultrasonic spraying technology, the prepared photoresist coating is significantly higher than the traditional spin coating in terms of microstructure wrapping and uniformity Craft.
The ultrasonic spraying system can precisely control the flow rate, coating speed and deposition volume. Low-speed spray shaping defines atomized spray as a precise and controllable pattern to avoid excessive spray when producing a very thin and uniform layer. The ultrasonic spray system can control the thickness from sub-micron to more than 100 microns, and can coat any shape or size.