Specific Process Knowledge/Lithography/Coaters/Spin Coater: Gamma UV processing: Difference between revisions
No edit summary |
|||
| (8 intermediate revisions by 2 users not shown) | |||
| Line 13: | Line 13: | ||
*Spin coating | *Spin coating | ||
*Soft baking | *Soft baking | ||
'''Features of Spin Coater: Gamma UV''' | '''Features of Spin Coater: Gamma UV''' | ||
*Cassette-to-cassette wafer handling | *Cassette-to-cassette wafer handling | ||
| Line 24: | Line 26: | ||
*Purging | *Purging | ||
*Cooling | *Cooling | ||
The top and bottom heaters of the VPO module are typically set to 120°C. The wafer is baked under a low vacuum (~0.35 bar) in order to heat and dehydrate the wafer before HMDS application. The HMDS is injected into the process chamber using nitrogen as a carrier gas. 10 liters per minute of dry nitrogen is bubbled through liquid HMDS before flowing into the chamber. The injection lasts until ambient pressuer is reached in the chamber. After the reaction time, the chamber is purged using nitrogen. Finally, the wafer is cooled on the cool plate. | The top and bottom heaters of the VPO module are typically set to 120°C. The wafer is baked under a low vacuum (~0.35 bar) in order to heat and dehydrate the wafer before HMDS application. The HMDS is injected into the process chamber using nitrogen as a carrier gas. 10 liters per minute of dry nitrogen is bubbled through liquid HMDS before flowing into the chamber. The injection lasts until ambient pressuer is reached in the chamber. After the reaction time, the chamber is purged using nitrogen. Finally, the wafer is cooled on the cool plate. | ||
| Line 34: | Line 38: | ||
*Spin-off | *Spin-off | ||
*Backside rinse using PGMEA | *Backside rinse using PGMEA | ||
The wafer is first centered on the spindle chuck and held in place by vacuum. If static dispense is specified in the process, the spindle remains static during the ensuing resist dispense. In the case of dynamic dispense, the spindle is accelerated to a low spin speed before the resist is dispensed. Using too high spin speed during dispense can cause surface wetting issues, while a too low spin speed causes the resist to flow onto the backside of the wafer. The resist is dispensed through the dispense arm, positioned over the center of the wafer. The resist pump administers a volume of resist which depends on the substrate size. | The wafer is first centered on the spindle chuck and held in place by vacuum. If static dispense is specified in the process, the spindle remains static during the ensuing resist dispense. In the case of dynamic dispense, the spindle is accelerated to a low spin speed before the resist is dispensed. Using too high spin speed during dispense can cause surface wetting issues, while a too low spin speed causes the resist to flow onto the backside of the wafer. The resist is dispensed through the dispense arm, positioned over the center of the wafer. The resist pump administers a volume of resist which depends on the substrate size. | ||
The spin-off cycle determines the thickness of the resist coating. The thickness is primarily a function of the spin-off speed and the spin-off time, both following an inverse power-law | The spin-off cycle determines the thickness of the resist coating. The thickness is primarily a function of the spin-off speed and the spin-off time, both following an inverse power-law. The acceleration to the spin-off speed also influences the thickness, but the effect is dependent on previous steps. The spin-off is usually a simple spin at one speed, but it may be comprised of several steps at different spin speeds. After spin-off, the wafer is decelerated. | ||
Dependent on the spin speeds used in the various steps of the spin coating, resist may creep over the edge of the wafer and onto the backside. Also, some resists tend to leave fine strings of resist protruding from the edge of the wafer, or folded onto the backside, an effect sometimes referred to as "cotton candy". This resist will contaminate the soft bake hotplate, and thus subsequent wafers with resist. In a backside rinse step, solvent administered through a nozzle to the backside of the wafer while spinning dissolves the resist and washes it away. After the rinse, a short spin dries the wafer before the soft bake. Backside rinse may be done as part of the spin-off step(s). During the backside rinse solvent inevitably creeps onto the front side of the wafer, and may remove the resist coating on the edge of the wafer. As an alternative to backside rinse, a wafer which is left dirty on the backside by the spin coat process may be soft baked in proximity in order to protect the hotplate from contamination. This leaves front side coating intact, but also leaves the backside dirty. | Dependent on the spin speeds used in the various steps of the spin coating, resist may creep over the edge of the wafer and onto the backside. Also, some resists tend to leave fine strings of resist protruding from the edge of the wafer, or folded onto the backside, an effect sometimes referred to as "cotton candy". This resist will contaminate the soft bake hotplate, and thus subsequent wafers with resist. In a backside rinse step, solvent administered through a nozzle to the backside of the wafer while spinning dissolves the resist and washes it away. After the rinse, a short spin dries the wafer before the soft bake. Backside rinse may be done as part of the spin-off step(s). During the backside rinse solvent inevitably creeps onto the front side of the wafer, and may remove the resist coating on the edge of the wafer. As an alternative to backside rinse, a wafer which is left dirty on the backside by the spin coat process may be soft baked in proximity in order to protect the hotplate from contamination. This leaves front side coating intact, but also leaves the backside dirty. | ||
| Line 49: | Line 54: | ||
|- | |- | ||
| | | | ||
*[http://labmanager.dtu.dk/d4Show.php?id=5123&mach=359 The QC procedure for Spin Coater: Gamma UV]<br> | *[http://labmanager.dtu.dk/d4Show.php?id=5123&mach=359 The QC procedure for Spin Coater: Gamma UV] - '''requires login'''<br> | ||
*[http://labmanager.dtu.dk/view_binary.php?fileId=4211 The newest QC data for Spin Coater: Gamma UV] | *[http://labmanager.dtu.dk/view_binary.php?fileId=4211 The newest QC data for Spin Coater: Gamma UV] - '''requires login''' | ||
{| {{table}} | {| {{table}} | ||
| align="center" | | | align="center" | | ||
| Line 104: | Line 109: | ||
|- | |- | ||
| | | | ||
*[http://labmanager.dtu.dk/d4Show.php?id=5123&mach=359 The QC procedure for Spin Coater: Gamma UV]<br> | *[http://labmanager.dtu.dk/d4Show.php?id=5123&mach=359 The QC procedure for Spin Coater: Gamma UV] - '''requires login'''<br> | ||
*[http://labmanager.dtu.dk/view_binary.php?fileId=4211 The newest QC data for Spin Coater: Gamma UV] | *[http://labmanager.dtu.dk/view_binary.php?fileId=4211 The newest QC data for Spin Coater: Gamma UV] - '''requires login''' | ||
{| {{table}} | {| {{table}} | ||
| align="center" | | | align="center" | | ||
| Line 165: | Line 170: | ||
Test results: | Test results: | ||
{|border="1" cellspacing=" | {|border="1" cellspacing="1" cellpadding="10" style="text-align:left;" | ||
|- | |- | ||
| Line 210: | Line 215: | ||
Test results: | Test results: | ||
{|border="1" cellspacing=" | {|border="1" cellspacing="1" cellpadding="10" style="text-align:left;" | ||
|- | |- | ||
| Line 247: | Line 252: | ||
|} | |} | ||
==AZ MiR 701 (29cps) coating== | ==AZ MiR 701 (29cps) coating== | ||
| Line 358: | Line 362: | ||
|taran | |taran | ||
|4" wafer, no HMDS. 9 points on one wafer, exclusion zone 5mm | |4" wafer, no HMDS. 9 points on one wafer, exclusion zone 5mm | ||
|- | |||
|-style="background:WhiteSmoke; color:black" | |||
|Silicon with native oxide | |||
|4.24 µm | |||
|0.5% | |||
|7/1 2025 | |||
|taran | |||
|Old sequence (proximity bake and only 60s by mistake). | |||
4" wafer, with HMDS. 9 points on one wafer, exclusion zone 5mm | |||
|- | |||
|-style="background:WhiteSmoke; color:black" | |||
|Silicon with native oxide | |||
|3.99 µm | |||
|0.3% | |||
|7/1 2025 | |||
|taran | |||
|New sequence with contact bake. | |||
4" wafer, with HMDS. 9 points on one wafer, exclusion zone 5mm | |||
|} | |} | ||
==AZ nLOF 2020 coating== | ==AZ nLOF 2020 coating== | ||