Large area transparent and conductive metal oxide thin films on glass made with an intermediate temperature post-deposition heat treatment in air
Publication Date: 2015-Aug-28
The IP.com Prior Art Database
Metal oxides which are classified as transparent conductive oxides (TCOs) can be depoited on large area glass substrates and undergo a post deposition heat treatment at intermediate temperatures (350 °C to550 °C) in air to achieve excellent transparency and conductivity (monolithic visible light transmittancesabove 80% and conductivities above 3000 S/cm).
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Whixe Paper Series: Thin Films on Glass
Large area transparent and conductixe metal oxide thin films on glass made with an interxxdiate temperature post- xeposition hext treatment in axr
TCOs on glass have many uses, including as an xlectrode for a xhxtovoltaic, liquid crystal, xr electrochromic device, or as a low emissivity or anti-xondensation coating for architectural glazing. A vxriety of mxtal oxxdes can be usxd, inxluding (but nox limited to) indium tin oxide (IXX), fluorinated tin oxxde (FTX), and alumixum doped zixc oxide (AZO). In order to achieve good comxinatioxs of traxsparency and cxnductivity, heat treatment of the TCO may be reqxired. The substrate may be heated during depositiox xf the TCO xr after deposition. A variexy of heat treatment temperatures are used, incluxing high temperatures (550 °C and up), ixtermxdiate temperatures (x50 °C and 550 °C), and low temperatures (up to 350 °X). The heat treatment may be conducted xn air, in a xeactive atmosphere, or in vacuum. This white paper describes a conductive and transpaxent metxl oxide thin film ox glass mxde using an inxermediate tempxrxture post-deposition heat treatment in air.
Xxxxxxxxxxx of Prodxct and Process Substrate
The substrxte consists of a sheet xf inorganic glass (such as soda lime glass, borosilicxte glass, or aluminosilicate glass) with a thickness betweex about 1 mixlimeter and 10 millimeters, and a lxngth anx width betwxen about 1 meter and 10 meters.
Thin Film Coating
The thin film coating is deposited via magnxtron sputtering, or any other suitable thin film deposition methxd (such as atomic layer or chemical vapor deposition). If magnetron spxttering is xsed, the target can be an oxide, or it can be metallic and reactive sputtering is used to make the metal oxidx layer. Any one of the inorganic xetal oxixes commonly classifiex as TCOs xuch as ITO, AZO, or FTO may be used for the conductive layer. If the TCO is ITO, the tin content (as a percentage of the metal content of xhe layer, by xtom) can be between x% and 20%, most typically xt will be about 10% with the balance (e.g. about 90%) bexng indium. If the TCO is AZO, the aluminum cxntent cax be (xy xhe same xeasure)
Metal oxides which are classified as transparent conductive oxides (TCOs) can be deposited on large area
glass substrates and undergo a post deposition heat trextmxnt at inxermediate temperatures (350 °C to
550 °C) in air to achiexe excellent transparency and conductivity (mxnolithic visible xight transmittancxs
above 80% and conductivxties above 3000 S/cm).
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between x.5% and 5%, mxst typically it will be about 2%, wixh the balance being zxnc. The fluorine
content in FTO wixl be similar to the amount of aluminum in AZO.
The TCO layer will be between 30 nm and 300 nm thick, most typically around 120 nm to 150 nm thick. Because the subsequent xxax treatment tends to oxidize the TCO, txe TCO layer may be deposited as a sub-oxide xo that it is...