Specific Process Knowledge/Lithography/EBeamLithography/JEOLPatternPreparation: Difference between revisions
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== Bulk and sleeve separation - double current exposure == | == Bulk and sleeve separation - double current exposure == | ||
Patterns that contain a mix of fine and large dimension structures can advantageously be broken into a low current and a high current exposure. In this way the fine features can be written at low current (and low speed) and the large structures can be written at high current (and high speed). Some patterns, for instance a fine electrode pattern with large bonding pads, can easily and manually be broken into a fine and coarse part and placed in two different layers. For many patterns this can however be very cumbersome but the process can also be automated with Beamer using "bulk and sleeve" setup. The concept is illustrated below. In this setup, Beamer will extract the periphery (sleeve) of a pattern into one layer and the bulk of structures into another layer. The bulk is oversized slightly (adding a bias) to ensure overlap between the two patterns at exposure. In this way structures can be defined with best possible edge definition while keeping exposure time down. [https://labmanager.dtu.dk/view_binary.php?fileId=5412 A Beamer flow with a default bulk and sleeve setup can be found here.] A | Patterns that contain a mix of fine and large dimension structures can advantageously be broken into a low current and a high current exposure. In this way the fine features can be written at low current (and low speed) and the large structures can be written at high current (and high speed). Some patterns, for instance a fine electrode pattern with large bonding pads, can easily and manually be broken into a fine and coarse part and placed in two different layers. For many patterns this can however be very cumbersome but the process can also be automated with Beamer using "bulk and sleeve" setup. The concept is illustrated below. In this setup, Beamer will extract the periphery (sleeve) of a pattern into one layer and the bulk of structures into another layer. The bulk is oversized slightly (adding a bias) to ensure overlap between the two patterns at exposure. In this way structures can be defined with best possible edge definition while keeping exposure time down. [https://labmanager.dtu.dk/view_binary.php?fileId=5412 A Beamer flow with a default bulk and sleeve setup can be found here.] A 500 nm sleeve with a 200 nm overlap is a good starting point. | ||