Lithography forms the backbone of a typical semiconductor device fabrication run. It enables us to ‘draw’/ ‘write’ micrometre or nanometre sized patterns, thereby defining the device dimensions.
In optical lithography, we ‘write’ using an ultraviolet (UV) beam, and pattern sizes can be as small as a few micrometres. Even smaller, nanometre-sized patterns can be written via e-beam lithography which uses a beam of electrons to ‘write’. In both cases, ‘writing’ is done on special light-sensitive (or electron-sensitive) materials known as resists. These are chemically processed after exposure (to light/ electron beam) to reveal the written pattern. Precise control over instrument, beam, chemicals and time is necessary to make any lithographic process a success.
IITBNF has multiple optical lithography tools with different pattern dimension limits. We also have a laser writer system that is capable of producing mask plates with micrometre-sized patterns for use in the optical lithography tools. The best resolution at IITBNF (< 20 nm) is achieved through our state-of-the-art e-beam lithography tool: Raith 150 Two. This tool can also be used for in-situ silicon dioxide and metal deposition using its electron beam induced deposition (EBID) feature. For both optical & e-beam tools, resist spinners dedicated to different types of resists are available with capabilities to process 2”, 4” & 8” wafers. All lithography tools are housed in separate clean rooms with tight control over temperature, humidity & lighting conditions.
|1||Double Sided Aligner (DSA)||20||litho/analytical|
|3||Karl Suss MJB3 Mask Aligner||17||litho/analytical|
|5||Spinner 2 inch (SU8, PPR)||17||litho/analytical|
|6||Spinner 2 inch (General Purpose)||17||litho/analytical|
|7||Spinner 8 inch (General Purpose)||20||litho/analytical|
|8||Spinner 2 inch (PPR)||20||litho/analytical|
|9||Spinner 4 inch (PMMA)||20||litho/analytical|
|10||Karl Suss MJB4 Mask Aligner||17||litho/analytical|
|11||Double Side Mask Aligner – Suss Microtech||29||litho/analytical|
|12||Spin Coater – Laurell||29||litho/analytical|