Microelectronics has advanced at a breakneck pace in both technology and application over the last two decades, to the point that it now affects practically every facet of commercial and military activity. Microelectronic device size and performance have significantly increased in recent years.
Electron beams can be utilized to create smaller patterns and have higher edge resolution than photolithography. Limited evidence suggests that the critical yield determinant, pattern defect density, may be lowered, and machines can be made to produce devices at a lower cost. This improved electron-beam technology is coming from the lab to become the next generation of microelectronic lithography and quality control instruments.
What is electron beam Lithography?
Scanning electron-beam lithography is a mature technique that arose from the early 1960s scanning electron microscope. Direct-write electron beam machines can sub-micrometer pattern definition and operate directly from design data. Photomasks and reticules for photolithography are also made with this material. Electron-beam lithography's main disadvantages are its limited throughput and expensive initial cost.
However, innovation in this industry is accelerating, and in the next two decades, less-expensive, higher-throughput devices will undoubtedly be produced. The ability to register correctly across tiny portions of a wafer, low defect concentrations and direct pattern production from circuit design data are three primary advantages of electron-beam lithography.
Negative and Positive E Beam Resist
The negative and positive families of photoactive or radiation-sensitive compounds are the most common but have fine distinctions. After being exposed to radiation, negative resists become less soluble, allowing the unexposed portions to be removed using a suitable solvent. On the other hand, positive resists become more soluble when exposed, allowing the exposed areas to be removed using a solvent developer. Both are generally made of organic polymers having physical and chemical characteristics that are compatible with semiconductor fabrication.
Hydrogen silsesquioxane in Photoresist Technology
The most often used negative e-beam lithography resist adhesion is hydrogen silsesquioxane (HSQ). The ultrahigh resolution of HSQ hydrogen silsesquioxane resists one of its most significant advantages. However, because of its limited shelf life, it is more expensive. A new sort of dry powder HSQ resists resin (DisChem, Inc.) was proposed as a replacement, with an unlimited shelf life.
Before exposure, a tiny amount of the powder can be dissolved in a solvent as needed. Furthermore, the resolution and sensitivity properties of this powder HSQ resist are comparable. A 7.5 nm half-pitch nested “L” shape structure is created by utilizing a high-contrast development procedure with a salty developer.
