Nanolithography

 
 

Nanolithography is a common term for various techniques that enable manufacturing of nanoscopic structures. Loosely speaking, nanolithography is capable of "printing" features (lines, dots, etc.) with the size of only a few nanometers. One of the most popular methods is to use a high energy beam (electron, laser, ion, ...) as a writing tool that draws the pattern image onto the substrate. The substrate is covered with a thin film of polymer, called resist. The resist is modified by exposure to the beam, which subsequently enables the formation of the pattern shaped structure on the substrate at the end of the process.

Nanolithography is typically used for fabrication of submicron electrodes, quantum electronic devices and circuits, but it is not limited to only this type of applications. It is an alternative to well established optical lithography widely used in semiconductor industry. The main difference is that in the case of nanolithography direct illumination without mask is used. Unfortunately this means much lower throughput, but the benefit is higher resolution and greater flexibility. This makes nanolithography particularly interesting for laboratories and research departments where small scale, low cost production and the ability to quickly adapt the pattern form is desired.

We fabricate high resolution submicron structures with the help of electron beam lithography (EBL) and with laser lithography. Performance of the latter does not match the EBL, as it is at the border of the micron range for now, but we hope to improve it with time. We perform it with laser direct imaging (LDI) system, which has been recently developed in Slovenian company LPKF Laser & Electronics. For the purposes of EBL we use converted scanning electron microscope (Jeol JSM-7600F) upgraded with accessory equipment for lithography (XENOS).