Specific Process Knowledge/Lithography/UVLithography: Difference between revisions

#'''Complete the TPT Lithography course''': [[LabAdviser/Courses/TPT_Lithography|Lithography Tool Package Training]].

#'''Mask''': If you wish to use a mask aligner, order a photomask for your UV process. Instructions on how to order a photomask can be found <u>[[Specific_Process_Knowledge/Pattern_Design#Mask_Ordering_and_Fabrication|here]]</u>.

'''Cleanroom work:'''

#'''Substrate pretreatment''': In many processes it is recommended to <u>[[Specific_Process_Knowledge/Lithography/Pretreatment|pretreat or prime]]</u> your wafer before spin-coating. In some <u>[[Specific_Process_Knowledge/Lithography/Coaters|spin-coaters]]</u>, these pretreatment processes are included in the spin coating of resist.  

#'''Resist Type''': Choose the type of resist you wish to use: a list of UV lithography resist types available at DTU Nanolab can be found <u>[[Specific_Process_Knowledge/Lithography/Resist/UVresist|on this page]]</u>.

##Positive tone resist: Resist exposed to UV light will be dissolved in the developer. The mask openings are an exact copy of the resist pattern which is to remain on the wafer.

##Negative tone resist: Resist exposed to UV light will become polymerized and difficult to dissolve. The mask openings are an inverse copy of the resist pattern which is to remain on the wafer.

#'''Thickness of resist''': In general, it is recommended to work at or below an aspect ratio of ~1, i.e. where the width of the pattern is larger than the thickness of the resist. Furthermore, when you decide the resist thickness, consider which transfer you need:

##For <u>[[Specific_Process_Knowledge/Lithography/LiftOff|lift-off]]</u> processes, we recommend resist thickness at least 5 times larger than the thickness of the metal to be lifted.

##For dry etch or wet etch processes, investigate the resist etch rate of your process as this might limit the minimum thickness of your resist.

#'''Spin Coater''': Do you wish to use a manual spin coater or an automatic spin coater? See a list of spin coaters <u>[[Specific_Process_Knowledge/Lithography/Coaters|here]]</u>.

#'''Exposure''': Choose which aligner you wish to use, and consider the exposure dose.

##You can find a list of mask aligners and maskless aligners <u>[[Specific_Process_Knowledge/Lithography/UVExposure|here]]</u>.

##You can find information on dose <u>[[Specific_Process_Knowledge/Lithography/UVExposure_Dose|here]]</u>.

#'''Development''': Choose which equipment you wish to use to develop your photoresist from <u>[[Specific_Process_Knowledge/Lithography/Development|this list]]</u>. Remember the development process influences the <u>[[Specific_Process_Knowledge/Lithography/Resist/UVresist|exposure dose]]</u>.

#'''Specify whether you wish to strip or lift-off your resist''': <u>[[Specific_Process_Knowledge/Lithography/Strip|strip]]</u> and <u>[[Specific_Process_Knowledge/Lithography/LiftOff|lift-off]]</u>.