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Sputter deposition

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[[{{PAGENAME}}]] is a [[physical vapor deposition]] method of thin film deposition in which a high-purity source material (called a cathode or target) is subjected to a gas plasma (typically [[argon]]). The energetic atoms in this gas plasma collide with the target material and knock off source atoms which then travel to the substrate and condense into a thin film.
==Method of operationEquipment==Sputtering is not typically done on liftoff samples or shadow masks. Therefore it is typically done as a blanket The LNF has 4 sputter deposition that will be patterned and etched later if patterning is needed. Samples should be clean and vacuumtools* [[Endeavor_M1_AlN_Sputter_Tool|Endeavor M1 Aluminum Nitride Sputter Tool]]* [[Lab 18-1|Lab 18-safe and should be handle a small amount of plasma heating. It is recommended that if there is any organic processing done to samples that they are cleaned in an oxygen plasma.1]]* [[Lab 18-2|Lab 18-2]]* [[PVD 75 Proline|PVD 75]]
Samples are introduced into a vacuum chamber (===Endeavor M1 Aluminum Nitride Sputter Tool==={{main|Endeavor_M1_AlN_Sputter_Tool}} *Materials deposited: AlN, Al*The Endeavor M1 tool is designed specifically for '''Piezoelectric AlN on either loaded in a vented chamber 4" or sent in from a loadlock) with the proper source target materials. The sample is heated and etched before deposition if the process requires it6" wafers'''. Ar is then introduced to the chamber until a desired sputtering pressure is reached and then power is applied the targets to strike a sputtering plasma. The target power It is then ramped up slowly while being shielded from the samples by a shutter. Once the pre-sputter sequence is finished, the shutter opens and the deposition is timed to achieve the desired thickness of film. The shutter closes, power is ramped down and the sputtering Ar gas is pumped out. Multiple films may be run by repeating this high temperature process that works only on certain substrates with a different source targets. The samples are then removed from the chamber specific seeding materials and the tool handler is pumped back designed to a low base pressureprocess both 4" (via 6" carrier) or 6" wafers.
==Applications=Lab 18-1==={{expand sectionmain|Lab 18-1}}*Materials Deposited: [[Al2O3|Al<sub>2</sub>O<sub>3</sub>]], [[Indium tin oxide|ITO]], [[Molybdenum|Mo]], [[Silicon|Si]], [[Silicon dioxide|SiO<sub>2</sub>]], [[Silicon nitride|Si<sub>3</sub>N<sub>4</sub>]], [[Tantalum|Ta]], [[Tantalum|Ta<sub>2</sub>O<sub>5</sub>]], [[Titanium|Ti]], [[Titanium dioxide|TiO<sub>2</sub>]], [[Vanadium|V]], [[Vanadium Pentoxide|V2O5]]*Lab 18-1 is a loadlocked magnetron sputter tool used for depositing '''less common metals, insulators, optical and semiconductive films.''' It has a variable-gated turbo pump and more sensitive gas flows that allow it to run more sensitive gas ratios (<1%) for reactive sputtering. It has a DC supply for conductive materials and RF supplies for electrically insulating materials. Deposition rates vary by material but are generally much slower for RF depositions. The tool supports 5 materials at a time, rotated using the [https://docs.google.com/a/lnf.umich.edu/spreadsheet/ccc?key=0AsWeTTMTotIfdExOSHBhSVQ4dUpyRFFpWE5icEMwZlE#gid=23|Lab 18-1 Target Change Calendar]
==Figures of merit=Lab 18-2==={{cleanupmain|section|reason=the subsection headings are wordy and there is a lot more depth than necessaryLab 18-2}}The figures of merit are described in the generic *Materials: [[Aluminum|Al]],[[Chromium|Cr]],[[Gold|Au]],[[Iridium|Ir]],[[Nickel|Ni]],[[Platinum|Pt]],[[Silver|Ag]],[[Physical vapor deposition Titanium| PVDTi]] page===Responses of figures of merit with parameter changes=======Deposition Rate, Stress[[Tungsten|W]], Resistivity and Step Coverage====[[Tungsten:Titanium-9:1|W-Ti]]Although many films (especially reactive films *Lab 18-2 is a loadlocked magnetron sputter tool used for mostly for '''depositing common and insulating compounds) may vary in their responseprecious metals.''' The tool supports 5 materials at a time, typical sputtering variables can be summarized in this trend chartrotated using the [https<gallery mode//docs.google.com/a/lnf.umich.edu/spreadsheet/ccc?key=0AsWeTTMTotIfdGxLMlpVZm1NSlF0SDJMU3hvRFctR1E#gid="packed13|Lab 18-hover" heights="600px">Sputter Process Trend Chart.jpg</gallery>2 Target Change Calendar]
====Uniformity=PVD 75 Sputter Tool===Uniformity is set by the material being {{main|PVD 75 Proline}}*Materials deposited and the geometry of the system: throw distance [[Al2O3|Al<sub>2</sub>O<sub>3</sub>]], [[Aluminum|Al]], [[Chromium|Cr]], [[Copper|Cu]], [[Cobalt|Co]], [[Iron|Fe]], [[Molybdenum|Mo]], [[Silicon|Si]], [[Silicon dioxide|SiO<sub>2</sub>]], [[Silicon nitride|Si<sub>3</sub>N<sub>4</sub>]], target size [[Nickel|Ni]], substrate rotation and deposition angle.[[Silver|Ag]], [[Titanium|Ti]], [[Tungsten|W]]*In sputtering, uniformity The PVD 75 tool is determined by throw distance and the shape designed specifically for '''point of use processing of materials not allowed or not currently in the deposition cone.**In the Denton and Lab 18 tools, smaller sources eject material from the face of a 3" target that is angled to cover around 1/2 of the substrate area. The substrate ''' It is rotated an open loop (non-loadlocked) tool with easier-to coat the entire area. Varying the angle will vary the throw distance and -change the amount deposited on the center and edge. The supplies have a set throw angle that is optimized for best uniformity.**In the ALN tool, the wafer is centered over two targets which are larger than the substrate. Uniformity Qualified users can be only be adjusted using the DC supply which raises and lowers change targets when they vent the power chamber to the center targetload their samples.
==Materials==
The following materials can be deposited using via Magnetron{{clarify}} sputter deposition at the LNF. Please note some materials are rarely used in these cases, additional work will be needed to validate process conditions and the rate of deposition.
*[[Aluminum|Aluminum(Al)]]
*[[Aluminum oxide|Aluminum oxide(Al2O3)]]
*[[Chromium|Chromium(Cr)]]
*[[Copper|Copper(Cu)]]
*[[Cobalt|Cobalt(Co)]]
*[[Gold|Gold (Au)]]
<!--*[[Germanium|Germanium(Ge)]]-->
*[[Germanium|Germanium(Ge)]]
*[[Iron|Iron(Fe)]]
*[[Indium tin oxide|Indium tin oxide(ITO)]]
*[[Molybdenum|Molybdenum(Mo)]]
*[[Nickel|Nickel (Ni)]]
*[[Platinum|Platinum(Pt)]]
*[[Silicon|Silicon (Si)]]
*[[Silicon dioxide|Silicon dioxide(SiO2)]]
*[[Silicon nitride|Silicon nitride(SiN)]]
*[[Silver|Silver(Ag)]]
*[[Tantalum|Tantalum(Ta)]]
*[[Tantalum oxide|Tantalum oxide(Ta2O5)]]
*[[Titanium|Titanium(Ti)]]
*[[Titanium oxide|Titanium oxide(TiO2)]]<!--*[[Titanium dioxide|Titanium dioxide(TiO2)]]-->*[[Tungsten|Tungsten(W)]]*[[Tungsten-Titanium 90:10|Tungsten-Titanium 90:10(W-Ti)]]*[[Vanadium|Vanadium(V)]]*[[ZincVanadium Pentoxide|ZincVanadium Pentoxide(ZnV2O5)]] ==Method of operation==Sputtering is not typically done on liftoff samples or shadow masks. Therefore it is typically done as a blanket deposition that will be patterned and etched later if patterning is needed. Samples should be clean and vacuum-safe and should be able to handle a small amount of plasma heating. It is recommended that if there is any organic processing done to samples that they are cleaned in an oxygen plasma.
==Equipment==Samples are introduced into a vacuum chamber (either loaded in a vented chamber or sent in from a loadlock) with the proper source target materials. The LNF has 4 sample is heated and etched before deposition if the process requires it. Ar is then introduced to the chamber until a desired sputtering pressure is reached and then power is applied the targets to strike a sputtering plasma. The target power is then ramped up slowly while being shielded from the samples by a shutter. Once the pre-sputter sequence is finished, the shutter opens and the deposition tools** [[AMS 2004 Aluminum Nitride Sputter Tool|AMS 2004 Aluminum Nitride Sputter Tool]]** [[Denton Explorer-14|Denton Explorer-14]]** [[Lab 18-1|Lab 18-1]]** [[Lab 18-2|Lab 18-2]]is timed to achieve the desired thickness of film. The shutter closes, power is ramped down and the sputtering Ar gas is pumped out. Multiple films may be run by repeating this process with a different source targets. The samples are then removed from the chamber and the tool is pumped back to a low base pressure.
===Lab 18-1=Applications=={{main|Lab 18-1expand section}}*Materials Deposited: [[Al2O3|Al<sub>2</sub>O<sub>3</sub>]], [[Indium-Tin-Oxide|ITO]], [[Molybdenum|Mo]], [[Silicon|Si]], [[Silicon Dioxide|SiO<sub>2</sub>]], [[Silicon Nitride|Si<sub>3</sub>N<sub>4</sub>]], [[Tantalum|Ta]], [[Tantalum|Ta<sub>2</sub>O<sub>5</sub>]], [[Titanium|Ti]], [[Titanium Dioxide|TiO<sub>2</sub>]]*Lab 18-1 is a loadlocked magnetron sputter tool used for depositing metals, insulators, optical and semiconductive films. It has a variable-gated turbo pump and more sensitive gas flows that allow it to run more sensitive gas ratios (<1%) for reactive sputtering. It has a DC supply for conductive materials and RF supplies for electrically insulating materials. Deposition rates vary by material but are generally mich slower for RF depositions. The tool supports 5 materials at a time, rotated using the [https://docs.google.com/a/lnf.umich.edu/spreadsheet/ccc?key=0AsWeTTMTotIfdExOSHBhSVQ4dUpyRFFpWE5icEMwZlE#gid=23|Lab 18-1 Target Change Calendar]
===Lab 18-2=Figures of merit=={{main|Lab 18-2}}*Materials: The figures of merit are described in the generic [[AluminumPhysical vapor deposition |AlPVD]]page===Responses of figures of merit with parameter changes=======Deposition Rate,[[Chromium|Cr]]Stress,[[Copper|Cu]],[[Gold|Au]],[[Iridium|Ir]],[[Nickel|Ni]],[[Platinum|Pt]],[[Silver|Ag]],[[Titanium|Ti]]Resistivity and Step Coverage====*Lab 18-2 is a loadlocked magnetron sputter tool used for mostly for depositing metals. It uses DC for conductive materials Although many films (especially reactive films and RF for electrically insulating materials. Deposition rates compounds) may vary by material but are generally slower for RF depositions. The tool supports 5 materials at a timein their response, rotated using the [httpstypical sputtering variables can be summarized in this trend chart://docs.google.com/a/lnf.umich.edu/spreadsheet/ccc?key=0AsWeTTMTotIfdGxLMlpVZm1NSlF0SDJMU3hvRFctR1E#gid=13|Lab 18-2 Target Change Calendar]
<gallery mode="packed-hover" heights==Denton Explorer==="600px">{{main|Denton Explorer}}Sputter Process Trend Chart.jpg*The Denton Explorer is an open-loop 2-source magnetron sputter tool used as a Lab 18 backup for depositing metal films</gallery>
===AMS 2004 Aluminum Nitride Sputter Tool=Uniformity===={{main|AMS 2004 Aluminum Nitride Sputter Tool}}*Materials Uniformity is set by the material being depositedand the geometry of the system: AlNthrow distance, Altarget size, substrate rotation and deposition angle.*The AMS tool In sputtering, uniformity is designed specifically for Piezoelectric AlN on 4determined by throw distance and the shape of the deposition cone.**In the PVD 75 and Lab 18 tools, smaller sources eject material from the face of a 3" waferstarget that is angled to cover around 1/2 of the substrate area. It The substrate is rotated to coat the entire area. Varying the angle will vary the throw distance and change the amount deposited on the center and edge. The supplies have a high temperature process set throw angle that works is optimized for best uniformity.**In the ALN tool, the wafer is centered over two targets which are larger than the substrate. Uniformity can be only on certain substrates with specific seeding matetrials be adjusted using the DC supply which raises and lowers the power to the handler is only designed for 4" wafers are this timecenter target.
==See also==
-->
==Further reading==
*[http://lnf-wiki.eecs.umich.edu/wiki/User_Resources#LNF_Tech_Talks_.28technology_seminar_series.29 LNF Tech Talk for PVD]
*[[Wikipedia:Sputter_deposition|General Overview: Wikipedia Sputter Deposition]]
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[[Category:PVD]]
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