When you think of manufacturing, you probably envision automotive factories churning out large ready-to-drive vehicles. While this is certainly a segment of the manufacturing industry, there are other processes performed on a much smaller level. Microfabrication, for instance, refers specifically to the process of fabricating small structures on a micrometre or smaller scale. It’s used in a wide range of manufacturing segments, including integrated circuits, semiconductors, microfluidic devices, solar panel cells, flat panel displays, sensors, fuel cells and more.
To put the size of microfabrication into perspective, a micrometre is the equivalent of one millionth of a metre, or one thousandth of a millimetre. This measurement is commonly used for wavelengths of infrared light, biological cells, and manufacturing processes in regards to microfabrication. Because its exceptionally small measurements, certain high-tech tools must be used when performing microfabrication work.
It’s important to note that microfabrication is a catch-all term used to describe all manufacturing processes that involve small structures on a micrometre or smaller scale. Other terms commonly used to describe these processes include micromaching, semiconductor processing, microelectronic fabrication, etc.
Microfabrication is a relatively new manufacturing process that was just recently created within the microelectronics industry. Companies essentially scaled down traditional machining processes like electro-discharge machining to create microfabrication.
So, how are microdevices created? The exact process varies depending on countless factors, including the company who’s manufacturing it, the tools to which workers have access, desired specifications and more. With that said, a typical microdevice is created first by depositing a film and then patterning the film with various micro features. Next, the company may etch away portions of the top layer of film.
Thin film plays a key role in microfabrication. Microfabricated products are typically created using multiple thin films. For electronic devices, these films may contain conductive metals that allow for the flow of electricity. Optical devices, on the other hand, may feature reflective or transparent films to improve visibility and clarity. And medical devices may have chemical films to inhibit microbial growth.
Microfabrication isn’t a quick or easy process by any means. Reports indicate that a typical memory chip requires approximately 30 litography, 10 oxidation, 20 etching, and 10 doping steps to fabricate. Companies often measure the difficulty of fabricating a product using mask count, which refers to the number of different pattern layers in the final product. If a product has 120 different layers, it also has a mask count of 120.