Difference between revisions of "DSEIII (PlasmaTherm/Deep Silicon Etcher)"

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(Recipes: linked to recipes)
(updated text, added Clamp text)
 
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|picture=DSEIII.jpg
 
|picture=DSEIII.jpg
 
|type = Dry Etch
 
|type = Dry Etch
|super= Don Freeborn
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|super= Brian Lingg
 
|phone= 805-893-3918x216
 
|phone= 805-893-3918x216
 
|location=Bay 2
 
|location=Bay 2
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= About =
 
= About =
   
The Si DRIE system is a Plasma-Therm DSEIII series system with a loadlock. The system has an Inductively Coupled Plasma (ICP) coil and a capactively coupled substrate HF (13.56MHz) and LF (100kHz) supplies to independently control plasma density and ion energy in the system. This system is dedicated to....... The fixturing is configured for 4" diameter Si wafers and uses a clamp to hold the sample on the RF chuck.
+
The Si DRIE system is a Plasma-Therm DSEIII series system with a loadlock. The system has an Inductively Coupled Plasma (ICP) coil and a capactively coupled substrate HF (13.56MHz) and LF (100kHz) supplies to independently control plasma density and ion energy in the system. This system is dedicated to deep silicon Bosch etching, although short O2 etches are also permitted. The fixturing is configured for 4" diameter Si wafers and uses a clamp to hold the sample on the RF chuck.
   
The materials allowed in the system are limited to Silicon, SiO<sub>2</sub>, Si<sub>3</sub>N<sub>4</sub>, SiO<sub>X</sub>N<sub>Y</sub>, and polymer films such as photoresist, PMMA, and polyimide. Other materials can be placed in the chamber.........
+
The materials allowed to be exposed in the system are limited to Silicon, SiO<sub>2</sub>, Si<sub>3</sub>N<sub>4</sub>, SiO<sub>X</sub>N<sub>Y</sub>, and polymer films such as photoresist, PMMA, and polyimide. Other materials can be placed in the chamber with staff approval.
   
Helium back-side cooling is used to keep the sample cool during the etch. Temperature control is very important as the polymer passivation layer is chemically etched away by the fluorine gas at elevated temperatures, resulting in loss of profile control. Pieces of wafers can be mounted onto 4" silicon wafers using .......... The etch rate is dependent on the open area of silicon (macro-loading effect) with large open area samples etching slower than small open area samples. Features with a high aspect ratio will also etch slower than more open areas. This is known as RIE lag or the micro-loading effect.
+
Helium back-side cooling is used to keep the sample cool during the etch. Temperature control is very important as the polymer passivation layer is chemically etched away by the fluorine gas at elevated temperatures, resulting in loss of profile control.
  +
  +
It is very important that your wafer does not stick to the top-side clamp in the chamber. The clamp will get hot during long etches, causing thick photoresists to soften and adhere to the clamp, resulting if wafer loss or breakage.
  +
  +
'''Users must remove photoresist from the wafer edge''' to prevent this. We have photolithographic methods for performing this cleanly, or simple swabbing with EBR100 will also suffice.
  +
  +
Pieces of wafers can be placed onto 4" silicon wafers, or mounted as long as material does not get on the clamp. It is common for through-silicon etches to use a carrier wafer, often bonded with wax on the Logitech bonder, and excess wax removed to ensure not adhesion to the clamp.
  +
  +
The etch rate is dependent on the open area of silicon (macro-loading effect) with large open area samples etching slower than small open area samples. Features with a high aspect ratio will also etch slower than more open areas. This is known as RIE lag or the micro-loading effect.
  +
  +
The in-situ laser monitor installed on this system allows for repeatable etches and endpoint detection via continuous optical monitoring of the wafer reflectivity in a user-determined location, through a porthole on the chamber.
   
 
= Detailed Specifications =
 
= Detailed Specifications =
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*C<sub>4</sub>F<sub>8</sub>, SF<sub>6</sub>, O<sub>2</sub>, Ar, N<sub>2</sub> gases available
 
*C<sub>4</sub>F<sub>8</sub>, SF<sub>6</sub>, O<sub>2</sub>, Ar, N<sub>2</sub> gases available
 
*He-back-side cooling
 
*He-back-side cooling
  +
*100mm wafer held down with ceramic clamp., single-load
  +
**Users must ensure thick photoresists or other substances do not contact the clamp, to prevent wafer stiction and breakage.
 
*Windows-based Cortex software control of process and wafer handling
 
*Windows-based Cortex software control of process and wafer handling
*Allowed materials: Silicon, SiO<sub>2</sub>, Si<sub>3</sub>N<sub>4</sub>, SiO<sub>X</sub>N<sub>Y</sub>, and polymer films such as photoresist, PMMA, and polyimide; ..........
+
*Allowed materials: Silicon, SiO<sub>2</sub>, Si<sub>3</sub>N<sub>4</sub>, SiO<sub>X</sub>N<sub>Y</sub>, Al, Al2O3, and polymer films such as photoresist, PMMA, and polyimide; CrystalBond wax for mounting to carrier wafer (ask staff before using oil).
*Realized etch rates (including passivation steps) for Bosch process of >8 um / min. Selectivity to resist > 80:1 for low aspect ratio.
+
**Realized etch rates (including passivation steps) for Bosch process of >8 um / min. Selectivity to resist > 80:1 for low aspect ratio.
*Laser monitoring with camera and etch simulation software for SOI etching - Intellemetrics
+
*Laser monitoring with camera and etch simulation software: [[Laser Etch Monitoring|Intellemetrics LEP 500]]
   
 
=Documentation=
 
=Documentation=
 
*{{file|DSEIII Operating Instructions.pdf|DSEIII Operating Instructions}}
 
*{{file|DSEIII Operating Instructions.pdf|DSEIII Operating Instructions}}
  +
*[[Laser Etch Monitoring|Laser Etch Monitoring procedures]]
 
 
 
= Recipes =
 
= Recipes =
* [https://www.nanotech.ucsb.edu/wiki/index.php/DSEIII_(PlasmaTherm/Deep_Silicon_Etcher) Plasma-Therm DSE-iii Recipes] - Recipes specific to this tool.
+
* [https://wiki.nanotech.ucsb.edu/wiki/index.php/ICP_Etching_Recipes#DSEIII_.28PlasmaTherm.2FDeep_Silicon_Etcher.29 '''Plasma-Therm DSE-iii Recipes'''] - Recipes specific to this tool.
 
* All [[Dry Etching Recipes]] - use this list to see other options for dry etching various materials.
 
* All [[Dry Etching Recipes]] - use this list to see other options for dry etching various materials.

Latest revision as of 08:45, 14 October 2020

DSEIII (PlasmaTherm/Deep Silicon Etcher)
DSEIII.jpg
Tool Type Dry Etch
Location Bay 2
Supervisor Brian Lingg
Supervisor Phone (805) 893-8145
Supervisor E-Mail lingg_b@ucsb.edu
Description Deep Silicon Etcher: Bosch MEMS Processes
Manufacturer Plasmatherm
Dry Etch Recipes
Sign up for this tool


About

The Si DRIE system is a Plasma-Therm DSEIII series system with a loadlock. The system has an Inductively Coupled Plasma (ICP) coil and a capactively coupled substrate HF (13.56MHz) and LF (100kHz) supplies to independently control plasma density and ion energy in the system. This system is dedicated to deep silicon Bosch etching, although short O2 etches are also permitted. The fixturing is configured for 4" diameter Si wafers and uses a clamp to hold the sample on the RF chuck.

The materials allowed to be exposed in the system are limited to Silicon, SiO2, Si3N4, SiOXNY, and polymer films such as photoresist, PMMA, and polyimide. Other materials can be placed in the chamber with staff approval.

Helium back-side cooling is used to keep the sample cool during the etch. Temperature control is very important as the polymer passivation layer is chemically etched away by the fluorine gas at elevated temperatures, resulting in loss of profile control.

It is very important that your wafer does not stick to the top-side clamp in the chamber. The clamp will get hot during long etches, causing thick photoresists to soften and adhere to the clamp, resulting if wafer loss or breakage.

Users must remove photoresist from the wafer edge to prevent this. We have photolithographic methods for performing this cleanly, or simple swabbing with EBR100 will also suffice.

Pieces of wafers can be placed onto 4" silicon wafers, or mounted as long as material does not get on the clamp. It is common for through-silicon etches to use a carrier wafer, often bonded with wax on the Logitech bonder, and excess wax removed to ensure not adhesion to the clamp.

The etch rate is dependent on the open area of silicon (macro-loading effect) with large open area samples etching slower than small open area samples. Features with a high aspect ratio will also etch slower than more open areas. This is known as RIE lag or the micro-loading effect.

The in-situ laser monitor installed on this system allows for repeatable etches and endpoint detection via continuous optical monitoring of the wafer reflectivity in a user-determined location, through a porthole on the chamber.

Detailed Specifications

  • 3500 W ICP coil power at 2 MHz and 500 W substrate bias at 13.56 MHz plasma generators
  • C4F8, SF6, O2, Ar, N2 gases available
  • He-back-side cooling
  • 100mm wafer held down with ceramic clamp., single-load
    • Users must ensure thick photoresists or other substances do not contact the clamp, to prevent wafer stiction and breakage.
  • Windows-based Cortex software control of process and wafer handling
  • Allowed materials: Silicon, SiO2, Si3N4, SiOXNY, Al, Al2O3, and polymer films such as photoresist, PMMA, and polyimide; CrystalBond wax for mounting to carrier wafer (ask staff before using oil).
    • Realized etch rates (including passivation steps) for Bosch process of >8 um / min. Selectivity to resist > 80:1 for low aspect ratio.
  • Laser monitoring with camera and etch simulation software: Intellemetrics LEP 500

Documentation

Recipes