{"action":"opened","issue":{"url":"https://api.github.com/repos/NanoLabStaff/nanolab/issues/25","labels_url":"https://api.github.com/repos/NanoLabStaff/nanolab/issues/25/labels{/name}","comments_url":"https://api.github.com/repos/NanoLabStaff/nanolab/issues/25/comments","events_url":"https://api.github.com/repos/NanoLabStaff/nanolab/issues/25/events","html_url":"https://github.com/NanoLabStaff/nanolab/issues/25","id":57329823,"number":25,"title":"PMMA lift-off 50-60 nm feature size, 110 nm pitch","user":{"login":"simenmm","id":3648091,"avatar_url":"https://avatars.githubusercontent.com/u/3648091?v=3","gravatar_id":"","url":"https://api.github.com/users/simenmm","html_url":"https://github.com/simenmm","followers_url":"https://api.github.com/users/simenmm/followers","following_url":"https://api.github.com/users/simenmm/following{/other_user}","gists_url":"https://api.github.com/users/simenmm/gists{/gist_id}","starred_url":"https://api.github.com/users/simenmm/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/simenmm/subscriptions","organizations_url":"https://api.github.com/users/simenmm/orgs","repos_url":"https://api.github.com/users/simenmm/repos","events_url":"https://api.github.com/users/simenmm/events{/privacy}","received_events_url":"https://api.github.com/users/simenmm/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":0,"created_at":"2015-02-11T15:24:29Z","updated_at":"2015-02-11T15:24:29Z","closed_at":null,"body":"by Simen Martinussen (simenmartinussen@gmail.com)\r\n\r\n***\r\n\r\n1. Spin coat PMMA (~80 nm)\r\n\r\n        200K PMMA A3.5\r\n        3500rpm for 120s\r\n        Ramp: 1000rpm/s for 3.5s  \r\n\r\n2. Soft bake\r\n\r\n        180°C for 60s \r\n\r\n3. Spin coat PMMA (~120 nm)\r\n\r\n        950K PMMA A4\r\n        3000rpm for 120s\r\n        Ramp: 1000rpm/s for 3s  \r\n\r\n4. Soft bake\r\n\r\n        180°C for 60s \r\n\r\n5. Exposure\r\n\r\n        Features: dots\r\n        HV: 20kV\r\n        Current: 42pA\r\n        Dose: 6 fC\r\n        Settling time: 100 µs\r\n\r\n6. Develop\r\n\r\n        9:1 IPA:DI water for ~15s (gently stirring)\r\n        Rinse in DI water for >30s\r\n        Dry with N2(g)\r\n\r\nLift-off successfully performed for evaporated 5 nm Ti/30 nm Au. Lift-off performed by immersion in acetone followed by acetone airbrushing.\r\n\r\nProcess writing speed with 100 µm write field: 5 hours and 45 minutes per square mm. EBL software stability problems was a serious issue for areas over 500x500 µm.\r\n\r\nPitch can possibly be reduced to 90 nm, but defocusing over large distances might be an issue. Settling time can possibly be reduced further as well.\r\n\r\nResist thickness values may be significantly inaccurate.\r\n\r\n![image](https://cloud.githubusercontent.com/assets/3648091/6149582/08d995e0-b20a-11e4-92e6-4639ea4601d8.png)\r\n"}}