View source for STS Pegasus 4/Processes/LNF Unswitched Poly

<!-- Make sure to add any other relevant categories
-->{{#ifeq: {{NAMESPACE}} | Template | | [[Category:Processes]]}}{{Infobox process
|image      = STS Pegasus_4_Unswitched_Poly_1_um.jpg
|caption    =
|technology = RIE
|material   = [[Silicon]]
|mask       = [[Photoresist|PR]], [[Silicon dioxide|SiO<sub>2</sub>]]
|chemicals  = 
|gases      = [[SF6|SF<sub>6</sub>]], [[C4F8|C<sub>4</sub>F<sub>8</sub>]], [[O2|O<sub>2</sub>]]
|created    = 
|modified   = 
|authors    =  }}
'''{{SUBPAGENAME}}''' is a single-step mixed-gas process intended for shallow silicon and thin film poly- and amorphous silicon etches.

{{note|The STS Pegasus is not designed for polysilicon etching. There are other tools at the LNF specifically designed for this, including the [[LAM 9400]] and the [[P5000 RIE]]. Please make a helpdesk ticket if you need assistance determining the correct tool or recipe for your process.|reminder}}

==Procedure==
Follow the standard operating procedure.

==Parameters==
{| class="wikitable" border="1" style="text-align: center"
|-
! Parameter
! Units
! Setpoint
|-
| ICP Power
| W
| 500
|-
| Bias Power
| W
| 20
|-
| Bias Pulsing
| Hz
| 40 (80%)
|-
| Pressure
| mTorr
| 5
|-
| C<sub>4</sub>F<sub>8</sub> Flow
| sccm
| 50
|-
| SF<sub>6</sub> Flow
| sccm
| 100
|-
| Ar Flow
| sccm
| 50
|-
| Chuck Temperature
| °C
| 20
|}

==Capabilities==

===Etch rate===
Etch rate will vary with feature size and loading.

{| class="wikitable" border="1" style="text-align: center"
|-
! Material
! Etch Rate
! Uniformity
|-
| Silicon
| 0.8 µm/min
| ?%
|}
{{note|Etch rate is feature size dependent: narrow openings will etch slower than larger open areas.|reminder}}

===Mask selectivity===
{| class="wikitable" border="1" style="text-align: center"
|-
! Material
! Etch Rate
! Uniformity
|-
| SPR 220
| 250 Å/min
| 6%
|-
| Silicon dioxide
| 90 Å/min
| 7%
|-
| Silicon nitride
| 220 Å/min
| 4%
|-
|-
| Low stress nitride
| 180 Å/min
| 4%
|}

===Etch profile===
{{note|This process etches semi-isotropically. Vertical to lateral etch rate is approximately 2:1.|reminder}}

==Limitations==

===Etch length===
This etch is designed for thin films and shallow etches (< 2 µm). It is not characterized for long processes.

===Feature size===
Remaining features that are narrower than the total depth will be etched away due to undercut during the etch.

===Open area===
Unknown