Description
SVGMarks is software for transforming distorted images by applying rotation and shear transformations based on the location of marks manually placed by a user. To apply the transformations, the correct dimensions (or aspect ratio) between the marks should be known.
SVGMarks is mainly used to transform images used in electron-beam lithography. However, SVGMarks can also be used to transform general purpose images, as long as the dimensions (or aspect ratio) between the features of the image are known.
Use in electron-beam lithography
Devices based on graphene and related two-dimensional (2D) materials are typically fabricated by patterning 2D materials deposited on a Si substrate by mechanical exfoliation. Such deposited 2D material flakes are randomly distributed on a chip. The probability of obtaining the desired flakes is very low (e.g., a few graphene monolayers per mm2). For this reason, the patterning of 2D materials (or any other sparse and randomly distributed set of objects) requires the deposition of 2D materials onto a prepatterned substrate containing a coordinate system (usually defined by a matrix of marks). The coordinate system is used to precisely locate the flakes on a chip, allowing the design of lithographic patterns. SVGMarks is used to process images of 2D material flakes and marks so that they can be imported into a design file.
Image processing is necessary for two reasons. Firstly, the coordinate system of the image is usually not the same as the coordinate system of the design file (even when images are taken with great care, there is always a slight rotation). Secondly, the exact dimensions of the image and the coordinates of the centre of the image are needed to scale the image and place it in the correct position in the design file.
General purpose use
SVGMarks can also be used to transform general purpose images (i.e., not related to electron-beam lithography). Such use is demonstrated at the end of the Manual.