Micro-electromechanical systems (MEMS) is a process technology used to create tiny integrated devices or systems that combine mechanical and electrical components. They are fabricated using integrated circuit (IC) batch processing techniques and can range in size from a few micrometers to millimetres.
These devices (or systems) have the ability to sense, control and actuate on the micro scale, and generate effects on the macro scale. MEMS originated in the United States, is also referred to as Microsystems Technology (MST) in Europe and Micromachines in Japan.

MEMS (Micro-Electro-Mechanical Systems) technology has revolutionized the way we interact with and perceive the world, enabling the creation of highly sophisticated and compact devices that improve our daily lives, enhance industrial processes, and drive technological advancements across multiple sectors.
The advent of microelectronics, particularly the development of the integrated circuit (IC), played a significant role in the growth of MEMS. The ability to fabricate miniaturized electronic components on a single chip paved the way for integrating mechanical components and sensors, giving rise to MEMS devices.

MEMS technology is a field of engineering and technology that involves the integration of mechanical elements, sensors, actuators, and electronics at the microscale level. It combines principles from various disciplines, including microfabrication, electronics, mechanics, and materials science, enabling the miniaturization, integration, and automation of complex systems, leading to a wide range of applications across industries. One of the earliest and most well-known MEMS devices is the accelerometer, which was developed for automotive airbag systems in the 1980s. Since then, MEMS technology has expanded to encompass a wide range of applications, including pressure sensors, microphones, inkjet printheads, microfluidic systems, optical switches, and many others

MEMS technology plays a vital role in advancing photolithography in semiconductor manufacturing. Its integration in positioning systems, optical devices, and fluidic systems enables enhanced precision, efficiency, and control over the lithographic process. By leveraging the capabilities of MEMS, photolithography can achieve higher resolution, improved yield, and greater flexibility in fabricating complex microscale devices.

In the context of photolithography, MEMS devices are employed to enhance the precision, efficiency, and reliability of the photolithographic process. One of the primary applications of MEMS technology in photolithography is the development of microscale positioning systems, that are compact, lightweight, and provide nanoscale precision. They can operate in real-time, enabling dynamic adjustments to compensate for any distortions or misalignments that may occur during the process. This capability significantly enhances the yield and quality of fabricated ICs.

Another significant application of MEMS technology in photolithography is the development of microscale optical devices. MEMS-based mirrors and lenses can be integrated into the photolithography system to manipulate and control the light used for exposing the photoresist on the wafer, that provides flexibility in adjusting exposure parameters, such as numerical aperture and illumination angle, to optimize the lithographic process for different feature sizes and design requirements.

MEMS technology also enables the development of microscale fluidic systems for chemical delivery and control in photolithography. Microfluidic channels and valves can be integrated into the photolithography equipment to precisely deliver photoresist, developer solutions, rinsing agents, and other chemicals to the wafer surface. This controlled and automated chemical delivery enhances process repeatability, reduces chemical consumption, and minimizes the contamination risks.