Specific Process Knowledge/Lithography/5214E: Difference between revisions

Latest revision as of 08:20, 13 April 2023

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Resist description

AZ 5214E is a positive UV photoresist with image reversal capability. It is considered to have good adhesion when wet etching.

Spin coating

Spin curves for AZ 5214E (old German version) using a 30 s spin-off, and a 60s @ 90°C softbake

Typical spin parameters:

Spin off: 30-60 s
Soft bake: 60 s @ 90°C

Image reversal

Typical image reversal parameters:

Reversal bake temperature: 110°C
Reversal bake time: 60 s
Flood exposure: 500 mJ/cm²

If 5214E is baked after exposure, the exposed resist will cross-link, making it insoluble in the developer. This is called the "Reversal bake". The reversal bake activates cross-linking of the exposed areas, which "reverses" the polarity of the design. When the substrate is flood-exposed after the reversal bake, the previously unexposed areas become soluble, and will be removed in the subsequent development. The image reversal procedure effectively makes AZ 5214E a negative resist.

The image reversal process greatly increases the sensitivity of AZ 5214E, and the dose of the image exposure is a critical parameter, especially if negative angled resist sidewalls are desired.
Half dose of the normal, positive process is a good starting point for optimization. Similarly, the reversal bake is also a critical step, and must be tightly controlled in order to achieve consistent results. If negative sidewalls are desired, 60 - 120 s at 110°C is recommended (as well as a resist thickness above 2 µm), but if straight sidewalls are desired, 60 - 120 s at 120°C can be used.

The flood exposure, on the other hand, is uncritical, and ~5 times the normal positive process dose is generally used.

Development

Development speed:

Puddle development in 2.38% TMAH (AZ 726 MIF): ~2 µm/min

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-'''Feedback to this section''': '''[mailto:labadviser@danchip.dtu.dk?Subject=Feed%20back%20from%20page%20http://http://labadviser.danchip.dtu.dk/index.php/Specific_Process_Knowledge/Lithography/5214E click here]'''
+{{:Specific Process Knowledge/Lithography/authors_generic}}
-AZ 5214E is a positive UV photoresist with image reversal capability.
+'''Feedback to this page''': '''[mailto:labadviser@nanolab.dtu.dk?Subject=Feed%20back%20from%20page%20http://labadviser.nanolab.dtu.dk/index.php/Specific_Process_Knowledge/Lithography/5214E click here]'''
+[[Category: Lithography|Resist]]
+[[Category: Resist|AZ 5214E]]
+__TOC__
+==Resist description==
+AZ 5214E is a positive UV photoresist with image reversal capability. It is considered to have good adhesion when wet etching.
 ==Spin coating==
+[[Image:5214Espincurves.JPG|500x500px|thumb|Spin curves for AZ 5214E (old German version) using a 30 s spin-off, and a 60s @ 90°C softbake]]
-[[Image:5214Espincurves.JPG|500x500px|thumb|Spin curves for AZ 5214E using a 30s spin-off, and a 60s@90°C softbake]]
+'''Typical spin parameters:'''
+*Spin off: 30-60 s
+*Soft bake: 60 s @ 90°C
 <br clear="all" />
 ==Image reversal==
+'''Typical image reversal parameters:'''
+*Reversal bake temperature: 110°C
+*Reversal bake time: 60 s
+*Flood exposure: 500 mJ/cm<sup>2</sup>
-If 5214E is baked after exposure, the exposed resist will cross-link, making it insoluble in the developer. If the substrate is flood exposed after the reversal bake, the areas not exposed in the initial image exposure become soluble, and will be removed in the subsequent development. This procedure effectively makes AZ 5214E a negative resist.
+If 5214E is baked after exposure, the exposed resist will cross-link, making it insoluble in the developer. This is called the "Reversal bake". The reversal bake activates cross-linking of the exposed areas, which "reverses" the polarity of the design. When the substrate is flood-exposed after the reversal bake, the previously unexposed areas become soluble, and will be removed in the subsequent development. The image reversal procedure effectively makes AZ 5214E a negative resist.
-The image reversal process greatly increases the sensitivity of AZ 5214E, and the dose of the image exposure is a critical parameter, especially if negative resist sidewalls are desired. Half dose of the normal, positive process is a good starting point for optimization. Similarly, the reversal bake is also a critical step, and must be tightly controlled in order to achieve consistent results. If negative sidewalls are desired, 100-120s at 110°C is recommended (as well as a thickness above 2µm). If straight sidewalls are desired, 100-120s at 120°C can be used. The flood exposure, on the other hand, is not critical, and double dose of the normal, positive process is generally used.
+The image reversal process greatly increases the sensitivity of AZ 5214E, and the dose of the image exposure is a critical parameter, especially if negative angled resist sidewalls are desired.<br>
+Half dose of the normal, positive process is a good starting point for optimization. Similarly, the reversal bake is also a critical step, and must be tightly controlled in order to achieve consistent results. If negative sidewalls are desired, 60 - 120 s at 110°C is recommended (as well as a resist thickness above 2 µm), but if straight sidewalls are desired, 60 - 120 s at 120°C can be used.
+The flood exposure, on the other hand, is uncritical, and ~5 times the normal positive process dose is generally used.
 ==Development==
+'''Development speed:'''
-A 1.5-2.2µm AZ 5214E resist film is fully developed in 60s using TMAH (AZ 726). Depending on the exposure dose, thicker coatings may develop in 1 min, but it is probably better to aim for a similar development speed (2µm/min).
+*Puddle development in 2.38% TMAH (AZ 726 MIF): ~2 µm/min