Specific Process Knowledge/Etch/DRIE-Pegasus

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The DRIE Pegasus tools at Danchip

In 2010 Danchip acquired DRIE-Pegasus 1 (at the time called DRIE-Pegasus). As a state-of-the-art etch tool with excellent performance and great flexibility, it grew immensely popular and by 2015 it was apparent that we needed yet another tool to cope with the demand. Therefore, in 2016 Pegasus 2 was acquired from a closed-down lab in Morocco and installed next to Pegasus 1.

Then, in 2017 we got our hands on a twin Pegasus system with cassette to cassette vacuum robot at a very reasonable price from a commerciel fab. The twin Pegasus system (will be called Pegasus 3 and 4) will be installed at the old cluster 2 location in cleanroom C1 from August 2018 onwards.

The DRIE-Pegasus 1 load lock and cassette loader in the Danchip cleanroom A-1
The-Pegasus 2 operator station and load lock in the Danchip cleanroom A-1
DRIE-Pegasus 1 DRIE-Pegasus 2
Serial MP0636 Serial MP0641


The Bosch process

The DRIE Pegasus tools are state-of-art silicon dry etchers that offer outstanding performance in terms of etch rate, uniformity etc. They use the so-called Bosch process to achieve excellent control of the etched features. Click HERE for more fundamental information of the system. As of 2017, completing the Dry Etch TPT course is mandatory for all new users. On the TPT web page you will find a version of the latest lecture slides - here you will find information as well.

Links to the individual pages for the Pegasi

Process information

SPTS process notation

Describing a process recipe on the Pegasus may sometimes be difficult because of the great flexibility of the instrument. A compact and precise notation is therefore required for the recipes. Click HERE to find a short description of the official SPTS notation.

Hardware changes

A few hardware modifications have been made on the Pegasus since it was installed in 2010. The changes are listed in the table below under hardware options.


DRIE-Pegasus 1 DRIE-Pegasus 2 DRIE-Pegasus 3 DRIE-Pegasus 4
Purpose (current or intended) 4" silicon etch workhorse Research tool with very limited number of users 6" silicon etch workhorse 6" dielectric etcher
Manufactured 2010 2010 ? ?
Serial MP0636 MP0641 ? ?
Electrode size 4" 6" 6" 6"
Hardware options ? ?

Equipment performance and process related parameters

Equipment DRIE-Pegasus
Purpose Primary
  • Dry etching of silicon
  • Dry etching of barc
Alternative
  • Black silicon
Performance Etch rates
  • Standard processes A and B up to 15 µm/min depending on etch load and feature size
  • Other processes: Any number from 200 nm/min to 10 µm/min
Uniformity
  • For standard processes better than 3 % across a 150 mm wafer.
Process parameter range RF powers
  • Coil Power 5 kW
  • Platen power 300/500 W (HF/LF)
Gas flows
  • SF6: 0 to 1200 sccm
  • O2: 0 to 200 sccm
  • C4F8: 0 to 400 sccm
  • Ar: 0 to 283 sccm
Pressure and temperature
  • Pressure range 4 to 250 mTorr
  • Temperature range -20 to 30 degrees C
Process options
  • Bosch processes with etch and dep cycles possibly split into three individually controllable parts
  • Parameter ramping during process steps
  • SOI option to reduce notching at buried
Substrates Batch size
  • # small samples on carriers
  • # 50 mm wafers: Bonded to carriers
  • # 100 mm wafers: Up to 18 wafers in a batch process
  • # 150 mm wafers: 1 wafer
Allowed materials
  • Silicon wafers
  • Quartz wafers need a (semi)conducting layer for clamping
Possible masking materials
  • AZ photoresist
  • zep resist
  • DUV stepper resist (barc + krf)
  • Oxides and nitrides
  • Aluminium (only very mild processes such as process C and nanoetches)

General Pegasus information

Wafer bonding

To find information on how to bond wafers or chips to a carrier wafer, click here.


Characterisation of etched trenches

Comparing differences in etched trenches requires a set of common parameters for each trench. Click here to find more information about the parameters used on the DRIE-Pegasus process development.

Material from SPTS