View source for Specific Process Knowledge/Lithography/Descum

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[[Category: Equipment |Lithography descum]]
[[Category: Lithography|Descum]]

=Plasma asher 1=
[[image:Descum Results aug 2019.png|right|frame|400x400px| Descum results plasma asher 1. September 2019]]

'''The user manual(s), quality control procedure(s) and results and contact information can be found in [http://labmanager.dtu.dk/function.php?module=Machine&view=view&mach=44 LabManager].'''

Descum of AZ5214E resist on 50mm silicon wafer. Wafer was placed horisontally in chamber on a 100 mm carier wafer.


'''Recipe 1:'''<br>
Note: Plasma asher was cold before use
*O2 flow: 70 ml/min
*N2 flow: 70 ml/min
*Power: 150 W
{| {{table}}
| align="center" | 
{| border="1" cellspacing="1" cellpadding="2"  align="left"
|- style="background:LightGrey"
|'''Ashing time (min)'''|| 1|| 2 || 5 || 7 || 10 || 10  
|- 
|'''Etched Thickness (nm)'''|| 14.2 || 16.3 || 47.6 || 123.2 || 854.3 || 862.1
|-
|}
|}


'''Recipe 2:'''<br>
Note: Plasma asher was cold before use
*O2 flow: 500 ml/min
*N2 flow: 0 ml/min
*Power: 500 W
{| {{table}}
| align="center" | 
{| border="1" cellspacing="1" cellpadding="2"  align="left"
|- style="background:LightGrey"
|'''Ashing time (min)'''|| 1|| 2 || 5 || 7 || 10 || 10  
|- 
|'''Etched Thickness (nm)'''||  || 8.1 || 32.9 || 271.1 || 495.6 || 446.2
|-
|}
|}


==Descum tests on UV resists==
''Conny Hjort & Jesper Hanberg, September 2019''

[[image:PA1_descum.jpg|right|frameless|400x400px| Different resist descum results plasma asher 1. August 2021]]

Descum of different resists, AZ5214E, AZ701 MiR and AZ2020 nLOF, on a single 100mm wafer was tested. Wafer was placed vertically in the middle of glass carrier. 

'''Recipe settings:'''<br>
Note: plasma Asher was cold before use.
*O2 flow: 70 ml/min
*N2 flow: 70 ml/min
Power: 150 W

Minor temperature rise during processing was observed, but not more than 5 degrees. Starting chamber pressure was around 0.5 mbar.

'''1,5 um AZ5214E resist'''
{| {{table}}
| align="center" | 
{| border="1" cellspacing="1" cellpadding="2"  align="center"
 
|- style="background:LightGrey"
|'''Ashing time (min)'''|| 1|| 2 || 3 || 5 || 7 
|- 
|'''Etched Thickness (nm)'''|| 6,28 || 102,99 || 76,92 || N/A || N/A 
|-
|}
|}

'''1,5 um AZ5214E resist placed horizontally in the carrier'''
{| {{table}}
| align="center" | 
{| border="1" cellspacing="1" cellpadding="2"  align="center"
 
|- style="background:LightGrey"
|'''Ashing time (min)'''|| 1|| 2 || 3 || 5 || 7 
|- 
|'''Etched Thickness (nm)'''|| 63,03 || 143,32 || 304,29  || 372,59 || N/A 
|-
|}
|}

'''1,5 um AZ701MiR resist'''
{| {{table}}
| align="center" | 
{| border="1" cellspacing="1" cellpadding="2"  align="center"
 
|- style="background:LightGrey"
|'''Ashing time (min)'''|| 1|| 2 || 3 || 5 || 7 
|- 
|'''Etched Thickness (nm)'''|| 268,88 || 199,54 || 219,03 || 200,86 || 292,15 
|-
|}
|}

'''1,5 um AZ 2020nLOF resist'''
{| {{table}}
| align="center" | 
{| border="1" cellspacing="1" cellpadding="2"  align="center"
 
|- style="background:LightGrey"
|'''Ashing time (min)'''|| 1|| 2 || 3 || 5 || 7 
|- 
|'''Etched Thickness (nm)'''|| 1,68 || 76,51 || 169,72 || 481,96 || 272,59 
|-
|}
|}
<br clear="all" />

=Plasma asher 2=
[[image:descum_graf.jpg|right|frame|355x355px|Descum results plasma asher 2 - recipe 1]]

Descum of AZ  Mir 701 resist on 100mm silicon wafer. Five wafers were placed vertically in chamber.

Experiment parameters:
{| {{table}}
| align="center" | 
{| border="1" cellspacing="1" cellpadding="2"  align="center"
|- style="background:LightGrey"
| ||O2 flow|| N2 flow || Power
|- 
|'''recipe 1''' || 100 || 100 || 150
|-
|'''recipe 2''' || 500 || 0 || 200
|-
|}
|}



'''recipe 1'''
{| {{table}}
| align="center" | 
{| border="1" cellspacing="1" cellpadding="2"  align="center"
 
|- style="background:LightGrey"
|'''Ashing time (min)'''|| 1|| 2 || 3 || 4 || 6 || 7 || 8 || 9 || 10 || 12 || 14 || 15 || 20
|- 
|'''Etched Thickness (nm)'''|| 8,7 || 5,1 || 12,5 || 6,2 || 31,8 || 86,0 || 25,7 || 46,8 || 38,3 || 49,7 || 59,4 || 140,1 || 360,7
|-
|'''Initial temperature (°C)'''|| 28 || 21 || 31 || 21 || 22 || 28 || 25 || 24 || 21 || 24 || 24 || 22 || 22
|-
|}
|}



[[image:graf_descum-recipe2.png|right|frame|355x355px|Descum results plasma asher 2 - recipe 2]]

'''recipe 2'''
{| {{table}}
| align="center" | 
{| border="1" cellspacing="1" cellpadding="2"  align="center"
 
|- style="background:LightGrey"
|'''Ashing time (min)'''|| 1	||2	||3	||4	||5	||6	||7	||8	||10	||12	||15	||20
|- 
|'''Etched Thickness (nm)'''||8,1	||9,4	||16,8	||55,2	||44,0	||47,5	||42,5	||55,1	||85,3	||122,4	||184,8	||305,9
|- 
|'''Initial temperature (°C)'''||22	||21	||21	||22	||22	||22	||21	||21	||20	||21	||21	||22
|-
|}
|}

We can observe linear dependance of etched material on time after etching 7 minutes and more (recipe 2).


Jitka Urbánková & Jesper Hanberg
December 2019

<br clear="all" />

=Plasma asher 3=

Plasma Asher 3 is specially used for control descum process after lithography. Please notice that you only can process one 4 inch wafer or one small sampel at a time.
Machine is equipped with 2 gaslines: oxygen and nitrogen, but all tests run with oxygen as recommended by Diener.

'''Ashing of  AZ MiR701 resist'''

You can use different strategy planing your descum: you can change power settings or you can vary chamber pressure during descum.

''Testing different power settings''

[[image:AZMIR701_power_settings.png|right|frame|400x400px| Descum results for different power settings]]

Recipe settings:
Kept oxygen and pressure settings constant at Oxygen: 5 sccm under process; Pressure: 0,2mbar and vary power.

Experiment parameters:
{| {{table}}
| align="center" | 
{| border="1" cellspacing="1" cellpadding="2"  align="center"
|- style="background:LightGrey"
| ||FW/REV|| C2/C1 || Power
|- 
|'''recipe 1''' || 50/0 || 52/31 || 50%
|-
|'''recipe 2''' || 100/0 || 53/31 || 100%
|-
|'''recipe 3''' || 20/0 || 51/34 || 20%
|-
|}
|}
<br clear="all" />

''Testing different pressure settings''

Recipe settings:
Kept power setting constant at Power: 100% and vary oxygen flow during process.

[[image:AZMIR701_pressure_settings.png|right|frame|400x400px| Descum results for different pressure settings]]


Experiment parameters:
{| {{table}}
| align="center" | 
{| border="1" cellspacing="1" cellpadding="2"  align="center"
|- style="background:LightGrey"
| ||FW/REV|| C2/C1 || Oxygen || Pressure
|- 
|'''recipe 1'''|| 100/0 || 53/31 || 5 || 0,2
|-
|'''recipe 2''' || 100/0 || 37/38 || 45 || 0,8
|-
|}
|}

<br clear="all" />

'''Ashing of AZ5214E resist'''

[[image:AZ5214E_pressure_settings.png|right|frame|400x400px| Descum results for different pressure settings]]

Recipe settings:
Kept power setting constant at Power: 100% and vary oxygen flow during process.


Experiment parameters:
{| {{table}}
| align="center" | 
{| border="1" cellspacing="1" cellpadding="2"  align="center"
|- style="background:LightGrey"
| ||FW/REV|| C2/C1 || Oxygen || Pressure
|- 
|'''recipe 1'''|| 100/0 || 53/31 || 17 || 0,4
|-
|'''recipe 2''' || 100/0 || 37/39 || 45 || 0,8
|-
|}
|}
<br clear="all" />