View source for DRIE: Bosch & Cryo ICP-RIE for Silicon

{{InstrumentInfobox|
|InstrumentName = DRIE
|HeaderColor = #FFE2B9
|ImageOne = Silicon-Microcones_Paul-A-Kempler.jpg
|ImageTwo = DRIE_Bosch-and-Cryo_ICP–RIE_.jpg
|InstrumentType = [[Equipment_List#Etching|Etching]]
|RoomLocation = B235 Steele
|LabPhone = 626-395-1532
|PrimaryStaff = [[Nathan S. Lee]]
|StaffEmail = nathslee@caltech.edu
|StaffPhone = 626-395-1319
|Manufacturer = Oxford Instruments
|Techniques = Bosch & Cryogenic Etch of Silicon
|EmailList =  kni-oxfordicp
|EmailListName = Oxford ICP
|Model = Plasmalab System 100
}}
== Description ==
The MEMS / Bosch / Cryo inductively-coupled plasma reactive-ion etch (ICP-RIE) is an Oxford Instruments Plasma Technology Plasmalab System 100 ICP-RIE 380 system that is optimized for silicon etching. This system is configured for deep reactive-ion etching (DRIE) via the Bosch process, allowing silicon etching with SF<sub>6</sub> and C<sub>4</sub>F<sub>8</sub> gases. Close-coupled gas pods are included in this system for fast Bosch switching. 
The silicon ICP-RIE has a variable temperature stage (-150 to 300 °C) to permit cryogenic etching of silicon with SF<sub>6</sub> and O<sub>2</sub> if needed. This system supports wafer sizes up to 6 inches and provides accurate deep etching capabilities for silicon only. 
===== Applications =====
* Deep silicon etch using Bosch process
* Cryogenic etch of silicon
* pseudo-Bosch etch of silicon
===== Allowed material in DRIE =====
* Si, Si<sub>x</sub>N<sub>y</sub>, SiO<sub>2</sub>, Ge
* PMMA/ZEP/SPR/AZ/maN resists, SiO<sub>x</sub>/Al<sub>2</sub>O<sub>3</sub> hard masks
* Buried/backside metal ok if never exposed (not an etch stop)
===== DRIE Gas List =====
* SF<sub>6</sub>
* C<sub>4</sub>F<sub>8</sub>
* O<sub>2</sub>
* Ar
* N<sub>2</sub>

== Resources ==
===== SOPs & Troubleshooting =====
* [https://caltech.box.com/s/0qe85zye5mjlgqxorxa77tzgqgblv3ep General Use SOP]
* [https://caltech.box.com/s/jesslkguhfgdl9pud83mmtm2ruf6vb50 Power Up Oxford ICP-RIE SOP]
* [https://caltech.box.com/s/29e5taof6r80d45lfb4sgbup1k6rebpx Gas Status Board SOP]

===== Process Documents =====
* [https://caltech.box.com/s/3n21r2o30u476ppnxfp657o3zbs9f0on Process Standards]
* [https://caltech.box.com/s/z3ibiol0xp1qwi6cyvnghbxs81p8j5q5 Silicon Waveguide Etch]
* [https://caltech.box.com/s/c622brbs1udx5hqc744jvdd7wtf2mw32 Bosch Si Etch]
* [https://caltech.box.com/s/v92jrijz2iijzzlnyrbzbolov7zvo3w0 High-Rate Bosch Si Etch]
* [https://caltech.box.com/s/daa9zeonjqphc8v963mi3lojo8me0u9j Cryo-Si Etch]
* [https://caltech.box.com/s/ekzldcen8pjhok0qbpdy796xvs3icae4 Isotropic Si Etch]
* [https://caltech.box.com/s/ymt2wqtkkjwcyw5c71f2adm2a1u041zn Etch chamber cleaning recipes]

===== Review Articles =====
* [https://caltech.box.com/s/3fnc4a7qeyr1up6kth599j7ojybka2vb Guidelines for Etching Silicon MEMS Structures]
* [https://caltech.box.com/s/j61w7vr4f8cdjr64jrnz1t37oizdhl7f Etch rates for MEMS Processing - Part I]
* [https://caltech.box.com/s/ls0jl268j4at6z39g6kv8wivevpq80eh Etch Rates for MEMS Processing - Part II]
* [https://caltech.box.com/s/cetpre7d66gssbhtaicnhtovyo6ngzjv Dry Etching of Electronic Oxides, Polymers, and Semiconductors]
* [https://caltech.box.com/s/pauf384duhejuwzfwan71eam7nkvdrxw Alumina etch masks for fabrication of high-aspect-ratio silicon micropillars and nanopillars]
* [https://caltech.box.com/s/q42u5q46nmx2hm53szub556kwcrc0oih David Henry's thesis on dry etching in the KNI's tools]

===== Manufacturer Manuals =====
* [https://labrunr.caltech.edu/machinefiles/125/LabRunr%20System%20Manual%20for%20Caltech%2094-219846.pdf Oxford Plasmalab System 100 DRIE Manual] (<i>login to LabRunr required</i>)
* [https://caltech.box.com/s/gclvux5tu28rpssvwncx5sm518uhmebl Edwards QDP 80 dry vacuum pump Manual]

== Specifications ==
===== Manufacturer Specifications =====
* [https://caltech.box.com/s/85mj9roas98jtwee9d22hk0wk9un54fl Manufacturer System Configuration]
===== System Features =====
* Universal base console that houses the electronic sub systems, control units, pneumatics, and turbomolecular pump
* PC 2000 Operating system 
* ICP process chamber with 200 mm pumping port, view port and end-point-detection ports for optical emission spectrometer and laser interferometer
* Variable height 240 mm Cryo RIE electrode 
* Parameter ramping software
* 100 mTorr, temperature-stabilized capacitance manometer for process control with an active penning gauge for base pressure measurement
* 200 mm pumping port is fitted with a 200 mm variable gate valve for chamber isolation and process pressure control
* Close-coupled gas pod to ICP for two digital non-toxic mass-flow-controlled gas lines (SF<sub>6</sub>, and C<sub>4</sub>F<sub>8</sub>)
* Six line gas pod with three non-toxic digital mass-flow-controlled gas lines
* Alcatel 1300 l/s MAGLEV  turbo pump
* Single-wafer automatic insertion load lock with soft pump option
* Single user license for Anisotropic Silicon Etch Process (Bosch)
===== System Specifications =====
* Chamber wall heating: 80 &deg;C
* Cryo table range: -150 to 400 &deg;C
* ICP 380 mm remote high-density plasma source with 8 kW RF generator and automatic matching unit close-coupled to the source
* Substrate bias control by 30 / 300W RIE source
* Helium back-side wafer cooling