Method for Fabricating a Doped and/or Alloyed Semiconductor
The present invention is directed to methods for depositing doped and/or alloyed semiconductor layers, an apparatus suitable for the depositing, and products prepared therefrom.
1 . A method for depositing a semiconductor layer on a substrate, the method comprising:
sputtering a material from a target onto a substrate to provide a semiconductor layer, while simultaneously doping and/or alloying the semiconductor layer with a metalorganic precursor.
2 . The method of claim 1 , wherein the sputtering the material and the doping and/or alloying occur within a single deposition chamber.
3 . The method of claim 1 , wherein the doping and/or alloying comprises providing to the substrate a decomposition product of the metalorganic precursor.
4 . The method of claim 3 , wherein the decomposition of the metalorganic precursor occurs via plasma activation, thermal activation, or a combination thereof.
5 . The method of claim 1 , wherein the sputtering comprises a target that includes a metal selected from: zinc, aluminum, titanium, tin, indium, hafnium, an oxide thereof, and combinations thereof.
6 . The method of claim 1 , wherein the sputtering includes a process selected from:
magnetron sputtering and non-magnetron sputtering.
7 . The method of claim 6 , wherein the sputtering comprises an excitation provided by radiofrequency current, mid-frequency current, direct current, or pulsed direct current.
8 . The method of claim 1 , further comprising providing a reactive gas during the sputtering and the doping and/or alloying.
9 . The method of claim 1 , wherein the sputtering a material from a target comprises:
(a) providing a surface, wherein one or more portions of the surface include a target material;
(b) flowing a gas into a region proximate to the surface;
(c) generating a plasma in the region proximate to the surface;
(d) sputtering the target material from the surface; and
(e) depositing the sputtered target material on the substrate.
10 . The method of claim 9 , wherein the flowing a gas comprises an inert gas.
11 . The method of claim 9 , further comprising: reacting at least a portion of the sputtered target material with a reactive species.
12 . The method of claim 11 , wherein the reacting comprises providing a reactive oxidizing species to the substrate.
13 . The method of claim 1 , wherein the doping and/or alloying comprises:
(a) flowing a metalorganic precursor into the deposition chamber;
(b) decomposing the metalorganic precursor to form a doping and/or alloying species; and
(c) providing the doping and/or alloying species to the substrate.
14 . The method of claim 13 , wherein the flowing comprises providing the metalorganic precursor in an after-glow region of a plasma.
15 . The method of claim 13 , wherein the flowing includes a metalorganic precursor that contains a metal selected from: a group IIA element, a transition metal, a group III element, a group VI element, and combinations thereof.
16 . The method of claim 13 , wherein the flowing includes a metalorganic precursor containing a metal selected from: gallium, aluminum, indium, magnesium, cadmium, iron, and combinations thereof.
17 . The method of claim 13 , wherein the flowing includes a metalorganic precursor selected from: trimethylgallium, triethylgallium, tripropylgallium, triethylaluminum, tripropylaluminum, tributylaluminum, diethylaluminum hydride, dipropylaluminum hydride, dibutylaluminum hydride, trimethylindium, bismethylcyclopentadienyl magnesium, dimethylcadmium, bicyclopentadienyl iron, and combinations thereof.
18 . The method of claim 13 , wherein the flowing includes a metalorganic precursor containing gallium, and the sputtering comprises one or more targets that include zinc, aluminum, or a combination thereof.
19 . The method of claim 1 , wherein the sputtering the material and the doping and/or alloying provides a dynamic deposition rate for the semiconductor layer of about 5 nm·m/min to about 100 nm·m/min.
20 . A product prepared by the process of claim 1 .
21 . The product of claim 20 , wherein the product is a gallium-doped zinc oxide layer having a refractive index of less than about 1.80, as measured at a wavelength of about 600 nm.
22 . The product of claim 20 , wherein the product is a doped zinc oxide layer comprising aluminum, gallium, or a combination thereof in a molar concentration of about 0.1% to about 30%.
23 . The product of claim 22 , wherein the doped zinc oxide layer has a specific crystal orientation and comprises gallium in a molar concentration of about 0.1% to about 15%.
24 . The product of claim 22 , wherein the doped zinc oxide layer has a specific crystal orientation and comprises aluminum in a molar concentration of about 0.1% to about 15%.
25 . The product of claim 20 , wherein the product is a zinc oxide layer alloyed with magnesium, cadmium, or a combination thereof.
26 . The product of claim 20 , wherein the product is a doped and/or alloyed zinc oxide layer having a single crystalline orientation.
27 . An apparatus comprising a deposition chamber that includes:
(a) a surface that includes a target material;
(b) a cathode assembly for supporting the surface that includes a target material;
(c) a means for sputtering the target material from the surface;
(d) a gas source;
(e) a metalorganic precursor source; and
(f) a means for positioning a substrate a distance from the surface.
28 . The apparatus of claim 27 , wherein the cathode assembly includes a linear hollow cathode.
29 . The apparatus of claim 27 , wherein the gas source comprises an inert gas source and a reactive gas source.
30 . The apparatus of claim 27 , wherein the means for positioning a substrate is suitable for positioning a substrate about 3 cm to about 8 cm from the surface that includes a target material or from an exit aperture of a hollow cathode.
31 . The apparatus of claim 27 , wherein the means for positioning a substrate is suitable for positioning a substrate about 1 cm to about 4 cm from metalorganic precursor source.
32 . The apparatus of claim 27 , further comprising an oxidant source.