Difference between revisions of "RIE 3 (MRC)"

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(Updated SOP)
 
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|picture=RIE3.jpg
 
|picture=RIE3.jpg
 
|type = Dry Etch
 
|type = Dry Etch
|super= Brian Lingg
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|super= Lee Sawyer
|phone= 805-893-3918x210
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|phone= 805-893-2123
|location=Bay 3
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|location=Bay 2
|email=lingg@ece.ucsb.edu
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|email=lee_sawyer@ucsb.edu
 
|description = RIE #3 Fluorine-Based System MRC 51
 
|description = RIE #3 Fluorine-Based System MRC 51
 
|manufacturer = Materials Research Corporation (MRC)
 
|manufacturer = Materials Research Corporation (MRC)
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|toolid=26
 
|toolid=26
 
}}  
 
}}  
= About =
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==About==
  
 
This is a Materials Research Corporation RIE-51 parallel plate, 13.56 MHz system used for etching with fluorine-containing gases (CF<sub>4</sub>, SF<sub>6</sub>, and CHF<sub>3</sub>). The system is used primarily for etching of Si, SiO<sub>2</sub>, and Si<sub>3</sub>N<sub>4</sub> films. Metals such as tungsten may also be etched. Tool features include: six inch diameter water cooled cathode/substrate platform, pyrex cylinder for plasma confinement and gas flow control, adjustable cathode-anode spacing, fixed DC bias or RF power control and a HeNe laser etch monitor with chart recorder. It is turbo pumped and has no loadlock.  
 
This is a Materials Research Corporation RIE-51 parallel plate, 13.56 MHz system used for etching with fluorine-containing gases (CF<sub>4</sub>, SF<sub>6</sub>, and CHF<sub>3</sub>). The system is used primarily for etching of Si, SiO<sub>2</sub>, and Si<sub>3</sub>N<sub>4</sub> films. Metals such as tungsten may also be etched. Tool features include: six inch diameter water cooled cathode/substrate platform, pyrex cylinder for plasma confinement and gas flow control, adjustable cathode-anode spacing, fixed DC bias or RF power control and a HeNe laser etch monitor with chart recorder. It is turbo pumped and has no loadlock.  
  
CF<sub>4</sub>/O<sub>2</sub> and SF<sub>6</sub>/O<sub>2</sub> will etch Si, SiO<sub>2</sub> and Si<sub>3</sub>N<sub>4</sub> readily since free fluorine is readily liberated in the plasma. The oxygen (up to 40%) initially enhances the fluorine concentration resulting in a higher etch rate. The oxygen also minimizes polymer formation in CF<sub>4</sub>/O<sub>2</sub>. Too much Oxygen will compete for fluorine available, suppressing the etch rate. Argon can be added to increase the physical component of etching. The highest etch rates are achieved with SF<sub>6</sub> due to the ease of liberating fluorine compared with CF<sub>4</sub>. The relative etch rate decreases as one goes from Si to Si<sub>3</sub>N<sub>4</sub> to SiO<sub>2</sub>. CF4/H<sub>2</sub> and CHF3 can be used to selectivity etch SiO<sub>2</sub> over Si and resist due to increased polymer formation from the presence of hydrogen. This polymer layer is thicker on Si and resist than on SiO<sub>2</sub>. The trade-off is selectivity versus sidewall profile as the polymer will result in a tapered wall profile. Also, the polymer can be difficult to remove after etching.  
+
CF<sub>4</sub>/O<sub>2</sub> and SF<sub>6</sub>/O<sub>2</sub> will etch Si, SiO<sub>2</sub> and Si<sub>3</sub>N<sub>4</sub> readily since free fluorine is readily liberated in the plasma. The oxygen (up to 40%) initially enhances the fluorine concentration resulting in a higher etch rate. The oxygen also minimizes polymer formation in CF<sub>4</sub>/O<sub>2</sub>. Too much Oxygen will compete for fluorine available, suppressing the etch rate. Argon can be added to increase the physical component of etching. The highest etch rates are achieved with SF<sub>6</sub> due to the ease of liberating fluorine compared with CF<sub>4</sub>. The relative etch rate decreases as one goes from Si to Si<sub>3</sub>N<sub>4</sub> to SiO<sub>2</sub>. CF4 and CHF3 can be used to selectivity etch SiO<sub>2</sub> over Si and resist due to increased polymer formation from the presence of hydrogen. This polymer layer is thicker on Si and resist than on SiO<sub>2</sub>. The trade-off is selectivity versus sidewall profile as the polymer will result in a tapered wall profile. Also, the polymer can be difficult to remove after etching.  
  
The etches have good selectivity to many metals and semiconductors such as Ni, Al, Cr, Ti, GaAs, InP, and GaN. The system generally produces anisotropic etch profiles unless one goes into a purely chemical fluorine etch mode with higher pressure SF<sub>6</sub> processes. The system also has a strong loading effect so that larger substrates and open areas will require more feed gas and higher pressure to compensate. As a result, individual processes need to be characterized.  
+
The etches have good selectivity to many metals and semiconductors such as Ni, Al, Cr, Ti, GaAs, InP, and GaN. The system generally produces anisotropic etch profiles unless one goes into a purely chemical fluorine etch mode with higher pressure SF<sub>6</sub> processes. The system also has a strong loading effect so that larger substrates and open areas will require more feed gas and higher pressure to compensate. As a result, individual processes need to be characterized.
  
= Detailed Specifications =
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==Detailed Specifications==
  
*Etch gases include: CF<sub>4</sub>, CHF<sub>3</sub>, SF<sub>6</sub>, Ar, O<sub>2</sub>, H<sub>2</sub>  
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*Etch gases include: CF<sub>4</sub>, CHF<sub>3</sub>, SF<sub>6</sub>, Ar, O<sub>2</sub>
*Low 1 E -6 ultimate chamber pressure  
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*Low 1 E -6 ultimate chamber pressure
*13.56 Mhz excitation frequency  
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*13.56 Mhz excitation frequency
*Manual gas control  
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*Manual gas control
*Automatic pressure control  
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*Automatic pressure control
*Manual RF tuning network  
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*Manual RF tuning network
*Timer circuit for stopping the plasma  
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*Timer circuit for stopping the plasma
*HeNe laser monitoring for etch stop
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*Sample size limited to approximately 4 inches
*Sample size limited to approximately 4 inches  
 
 
*Masking materials include: Ni, photoresist (limited to low bias/power), Cr, Al
 
*Masking materials include: Ni, photoresist (limited to low bias/power), Cr, Al
  
=Documentation=
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==Documentation==
  
*[[media:RIE 3 Operationing instructions.pdf|Operating Instructions]]
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*[https://wiki.nanotech.ucsb.edu/w/images/a/a6/RIE_3_SOP_Rev_D.pdf RIE #3 Standard Operating Procedure]

Latest revision as of 10:28, 15 March 2021

RIE 3 (MRC)
RIE3.jpg
Tool Type Dry Etch
Location Bay 2
Supervisor Lee Sawyer
Supervisor Phone (805) 893-2123
Supervisor E-Mail lee_sawyer@ucsb.edu
Description RIE #3 Fluorine-Based System MRC 51
Manufacturer Materials Research Corporation (MRC)
Dry Etch Recipes
Sign up for this tool


About

This is a Materials Research Corporation RIE-51 parallel plate, 13.56 MHz system used for etching with fluorine-containing gases (CF4, SF6, and CHF3). The system is used primarily for etching of Si, SiO2, and Si3N4 films. Metals such as tungsten may also be etched. Tool features include: six inch diameter water cooled cathode/substrate platform, pyrex cylinder for plasma confinement and gas flow control, adjustable cathode-anode spacing, fixed DC bias or RF power control and a HeNe laser etch monitor with chart recorder. It is turbo pumped and has no loadlock.

CF4/O2 and SF6/O2 will etch Si, SiO2 and Si3N4 readily since free fluorine is readily liberated in the plasma. The oxygen (up to 40%) initially enhances the fluorine concentration resulting in a higher etch rate. The oxygen also minimizes polymer formation in CF4/O2. Too much Oxygen will compete for fluorine available, suppressing the etch rate. Argon can be added to increase the physical component of etching. The highest etch rates are achieved with SF6 due to the ease of liberating fluorine compared with CF4. The relative etch rate decreases as one goes from Si to Si3N4 to SiO2. CF4 and CHF3 can be used to selectivity etch SiO2 over Si and resist due to increased polymer formation from the presence of hydrogen. This polymer layer is thicker on Si and resist than on SiO2. The trade-off is selectivity versus sidewall profile as the polymer will result in a tapered wall profile. Also, the polymer can be difficult to remove after etching.

The etches have good selectivity to many metals and semiconductors such as Ni, Al, Cr, Ti, GaAs, InP, and GaN. The system generally produces anisotropic etch profiles unless one goes into a purely chemical fluorine etch mode with higher pressure SF6 processes. The system also has a strong loading effect so that larger substrates and open areas will require more feed gas and higher pressure to compensate. As a result, individual processes need to be characterized.

Detailed Specifications

  • Etch gases include: CF4, CHF3, SF6, Ar, O2
  • Low 1 E -6 ultimate chamber pressure
  • 13.56 Mhz excitation frequency
  • Manual gas control
  • Automatic pressure control
  • Manual RF tuning network
  • Timer circuit for stopping the plasma
  • Sample size limited to approximately 4 inches
  • Masking materials include: Ni, photoresist (limited to low bias/power), Cr, Al

Documentation