Specific Process Knowledge/Thermal Process/A4 Phosphor Pre-dep furnace: Difference between revisions

Latest revision as of 14:22, 4 August 2025

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This page is written by DTU Nanolab internal Thermal A4 Furnace A4

Phosphorus Pre-dep furnace (A4)

The Phosphorus Pre-dep furnace (A4) is mainly used to dope Si wafers with phosphorus. The furnace can also be used for dry oxidation of Si wafers or phosphorus phase layers created in the phosphorus doping/pre-deposition process.

The A4 furnace is the lowest furnace tube in the furnace A-stack positioned in cleanroom B-1. The furnaces in the A-stack are the cleanest of all furnaces in the cleanroom. Be aware of that all wafers (including new wafers) have to be RCA cleaned before they enter the furnace, and please check the cross contamination information in LabManager before you use the furnace.

Phosphorous doping of Si wafers

Phosphorus is an n-type dopant that can be diffused into Si wafers (normally p-type) to form an n-type layer near the wafer surface. The doping will change the electrical properties of the silicon, so that for instance conductive structures and etch stop layers can be made.

The phosphorus doping source is phosphoryl chloride (commonly called phosphorus oxychloride) which is a colourless liquid with the chemical formula POCl₃. Furthermore, an oxygen (O₂) flow is needed for the doping process. The POCl₃ is stored in a bubbler, and nitrogen (N₂) gas is flowing though the bubbler.

There are two primary steps within a phosphorus doping/pre-deposition process: A pre-deposition step and a diffusion/drive-in step. The final profile of the doping concentration near the wafer surface depends on the pre-deposition and the drive-in temperatures and times.

After the phosphorous pre-deposition process, a phosphorus doped silicon oxide layer, i.e. a phosphosilicate glass layer, remains in the surface of the wafers. This layer can be removed by hydroflouric acid (HF) in the BHF etch bath at the RCA cleaning bench. When the phosphosilicate glass layer has been removed, a drive-in process (an annealing or a thermal oxidation) is done.

Normally, only the phosphorous doping/pre-deposition is done the Phosphorus Pre-dep furnace (A4), while the drive-in process is done in the A3 Phosphorus Drive-in furnace.

Dry oxidation of Si wafers (or phosphorus phase layers created in the phosphorus doping/pre-deposition process)

For dry oxidation processes, oxygen (O₂) is used as oxidant.

The user manual, technical information and contact information can be found in LabManager:

Phosphorus Pre-dep furnace (A4)

Process knowledge

Dope with Phosphorus

Overview of the performance of the Phosphorus Pre-dep furnace and some process related parameters

Purpose		Phosphorus doping/pre-deposition using POCl₃ Dry oxidation using O₂. 0-300 nm Si₂
Process parameter range	Process Temperature	900-1150 ^oC
	Process pressure	1 atm (atmospheric pressure)
	Gases on the system	POCl₃ O₂ N₂
Substrates	Batch size	1-30 100 mm wafers
Substrates	Substrate materials allowed	Silicon wafers (RCA cleaned)

@@ Line 1: / Line 1: @@
-==A4 Furnace Phosphor pre-dep==
+'''Feedback to this page''': '''[mailto:thinfilm@danchip.dtu.dk?Subject=Feed%20back%20from%20page%20http://labadviser.danchip.dtu.dk/index.php/Specific_Process_Knowledge/Thermal_Process/A4_Phosphor_Pre-dep_furnace click here]'''
-[[Image:A4.JPG|thumb|300x300px|A4 Phosphorus pre-dep furnace: positioned in cleanroom 2]]
-A4 is a furnace to dope Si wafers with Phosphor to make conductive lanes, etch stops etc. The doping source is Phosphoryl chloride (commonly called phosphorus oxychloride) is a colourless liquid with the formula POCl<sub>3</sub>.
+''This page is written by DTU Nanolab  internal''
+[[index.php?title=Category:Equipment|Thermal A4]]
+[[index.php?title=Category:Thermal process|Furnace]]
+[[index.php?title=Category:Furnaces|A4]]
-A4 is the lowest furnace tube in the A-stack positioned in cleanroom 2. The A-stack together with furnace C2 are the cleanest of all our furnaces. Please be aware of which substrates are allowed to enter this furnace. Check the [http://www.labmanager.danchip.dtu.dk/view_binary.php?fileId=1250 cross contamination chart]. If you are in doubt, please send a mail to [mailto:furnace@danchip.dtu.dk furnace@danchip.dtu.dk].
+==Phosphorus Pre-dep furnace (A4)==
+[[Image:A4.JPG|thumb|300x300px|Phosphorus Pre-dep furnace (A4). Positioned in cleanroom B-1.''Photo: DTU Nanolab internal'']]
-'''The user manual(s), quality control procedure(s) and results, user APV(s), technical information and contact information can be found in LabManager:'''
+The Phosphorus Pre-dep furnace (A4) is mainly used to dope Si wafers with phosphorus. The furnace can also be used for dry oxidation of Si wafers or phosphorus phase layers created in the phosphorus doping/pre-deposition process.
-'''[http://www.labmanager.danchip.dtu.dk/function.php?module=Machine&view=view&mach=47 Phosphor Pre-dep]'''
+The A4 furnace is the lowest furnace tube in the furnace A-stack positioned in cleanroom B-1. The furnaces in the A-stack are the cleanest of all furnaces in the cleanroom. Be aware of that all wafers (including new wafers) have to be RCA cleaned before they enter the furnace, and please check the cross contamination information in LabManager before you use the furnace.
+'''Phosphorous doping of Si wafers'''
+Phosphorus is an n-type dopant that can be diffused into Si wafers (normally p-type) to form an n-type layer near the wafer surface. The doping will change the electrical properties of the silicon, so that for instance conductive structures and etch stop layers can be made.
+The phosphorus doping source is phosphoryl chloride (commonly called phosphorus oxychloride) which is a colourless liquid with the chemical formula POCl<sub>3</sub>. Furthermore, an oxygen (O<sub>2</sub>) flow is needed for the doping process. The POCl<sub>3</sub> is stored in a bubbler, and nitrogen (N<sub>2</sub>) gas is flowing though the bubbler.
+There are two primary steps within a phosphorus doping/pre-deposition process: A pre-deposition step and a diffusion/drive-in step. The final profile of the doping concentration near the wafer surface depends on the pre-deposition and the drive-in temperatures and times.
+After the phosphorous pre-deposition process, a phosphorus doped silicon oxide layer, i.e. a phosphosilicate glass layer, remains in the surface of the wafers. This layer can be removed by hydroflouric acid (HF) in the BHF etch bath at the RCA cleaning bench. When the phosphosilicate glass layer has been removed, a drive-in process (an annealing or a thermal oxidation) is done.
+Normally, only the phosphorous doping/pre-deposition is done the Phosphorus Pre-dep furnace (A4), while the drive-in process is done in the A3 Phosphorus Drive-in furnace.
+'''Dry oxidation of Si wafers (or phosphorus phase layers created in the phosphorus doping/pre-deposition process)'''
+For dry oxidation processes, oxygen (O<sub>2</sub>) is used as oxidant.
+'''The user manual, technical information and contact information can be found in LabManager:'''
+'''[http://labmanager.danchip.dtu.dk/function.php?module=Machine&view=view&mach=83 Phosphorus Pre-dep furnace (A4)]'''
 == Process knowledge ==
 *[[Specific Process Knowledge/Thermal Process/Dope with Phosphorus|Dope with Phosphorus]]
-==Overview of the performance of the Phosphor pre-dep furnace and some process related parameters==
+==Overview of the performance of the Phosphorus Pre-dep furnace and some process related parameters==
-{| border="2" cellspacing="0" cellpadding="0"
+{| border="2" cellspacing="0" cellpadding="2"
 |-
 !style="background:silver; color:black;" align="center"|Purpose
-|style="background:LightGrey; color:black"|Doping of Phosphor
-|style="background:WhiteSmoke; color:black"|
-|-
-!style="background:silver; color:black" align="center"|Performance
 |style="background:LightGrey; color:black"|
 |style="background:WhiteSmoke; color:black"|
-*Look at Process knowladge
+*Phosphorus doping/pre-deposition using POCl<sub>3</sub>
+*Dry oxidation using O<sub>2</sub>. 0-300 nm Si<sub>2</sub>
 |-
 !style="background:silver; color:black" align="center" valign="center" rowspan="3"|Process parameter range
@@ Line 34: / Line 53: @@
 |style="background:LightGrey; color:black"|Process pressure
 |style="background:WhiteSmoke; color:black"|
-*1 atm
+*1 atm (atmospheric pressure)
 |-
-|style="background:LightGrey; color:black"|Gasses on the system
+|style="background:LightGrey; color:black"|Gases on the system
 |style="background:WhiteSmoke; color:black"|
-*POCL<sub>3</sub>
+*POCl<sub>3</sub>
+*O<sub>2</sub>
+*N<sub>2</sub>
 |-
 !style="background:silver; color:black" align="center" valign="center" rowspan="2"|Substrates
 |style="background:LightGrey; color:black"|Batch size
 |style="background:WhiteSmoke; color:black"|
-*1-30 4" wafer (or 2" wafers) per run
+*1-30 100 mm wafers
 |-
-| style="background:LightGrey; color:black"|Substrate material allowed
+| style="background:LightGrey; color:black"|Substrate materials allowed
 |style="background:WhiteSmoke; color:black"|
-*Silicon wafers (new from the box or RCA cleaned)
+*Silicon wafers (RCA cleaned)
-*In doubt: look at the [http://www.labmanager.danchip.dtu.dk/view_binary.php?fileId=1250 cross contamination chart] or please send a mail to [mailto:furnace@danchip.dtu.dk furnace@danchip.dtu.dk]
 |-
 |}