[Music] this short video will teach you the basics of electron beam lithography lithography is a word that comes from ancient Greek meaning printing with stones with this technique a stamp is made by carving a pattern into a stone the stone is then coated in ink and pressed onto a substrate such as paper similar methods are used when making small micro scale devices or a pattern needs to be made repeatedly on waivers the two methods used are called electron beam lithography and photo lithography EBL uses electrons to print while photolithography uses light both methods use an
organic material called a resist which is sensitive either to electrons or light depending on the material used a thin coat of this resist is applied to the substrate in photo lithography the resist is exposed to light through a patterned mask that has been transferred onto the substrate wherever the mask allows light to reach the resist a chemical reaction occurs in which large resist molecules are broken down into smaller molecules after exposure the next step is called developing the area of the resist that has been exposed to light is removed by immersing the wafer in an
organic solvent the solvent dissolves only the small molecules that were produced during the exposure to light finally the pattern is transferred onto the substrate using one of two available methods method one is etching in which substrate is chemically removed from the pattern area that is not coated in resist after etching the remaining resist is removed revealing the pattern etched into the substrate surface method two is the liftoff technique in which a metal layer is deposited over the whole of the wafer the resist is then removed taking the metal there with it the only area that
now has a metal coating is the desired pattern where the resist had previously been removed in the developing step electron beam lithography uses the same process scheme but a focused electron beam is used for exposure the beam is accurately directed to positions on the wafer to form the pattern the electron beam exposes the pattern dot by dot and line by line which can be more time-consuming than photolithography however it is a more flexible system and does not require expensive masks the focused electron beam also allows feature sizes below 10 nanometers to be generated common applications
for EBL are rapid prototyping small batch production where electron beam lithography and photo lithography are used in conjunction as well as the fabrication of masks and imprint templates [Music]
