Method of growing oxide thin films
Process for producing silicon oxide containing thin films on a growth substrate by the ALCVD method. In the process, a vaporisable silicon compound is bonded to the growth substrate, and the bonded silicon compound is converted to silicon dioxide. The invention comprises using a silicon compound which contains at least one organic ligand and the bonded silicon compound is converted to silicon dioxide by contacting it with a vaporised, reactive oxygen source, in particular with ozone. The present invention provides a controlled process for growing controlling thin films containing SiO 2 , with sufficiently short reaction times.
1. An atomic layer deposition (ALD) process for producing a thin film comprising silicon dioxide on a substrate by alternating, saturating surface reactions, the process comprising:
contacting a substrate in a reactor with a vaporized silicon compound selected from the group consisting of amino substituted silanes and silazanes, wherein the silicon compound comprises at least one organic ligand, and wherein a substrate temperature is selected such that silicon compound chemisorbs to the substrate to form a single molecular layer and the silicon compound does not condense or decompose on the substrate;
removing unreacted vaporized organic silicon compound; and
converting the chemisorbed silicon compound into silicon dioxide by contacting the substrate with a reactive vaporized oxygen source compound, wherein the vaporized silicon compound and the reactive vaporized oxygen source compound are the only reactants used to form the silicon dioxide, wherein the reactive oxygen source is more reactive than water towards the silicon compounds, wherein the reactive oxygen source comprises an oxygen radical or a hydroxyl radical, and wherein when contacting the substrate the reactant flows continuously from an inlet of the reactor to an outlet of the reactor.
2. The process of claim 1 , wherein the substrate has a temperature of about 150-400° C. when contacted with the silicon compound.
3. The process of claim 1 , wherein the boiling point of the silicon compound is less than or equal to 400° C. at a pressure of 10 mbar.
4. The process of claim 1 , wherein contacting the substrate with a vaporized silicon compound and converting the chemisorbed silicon compound into silicon dioxide are both performed at essentially the same temperature.
5. The process of claim 1 , wherein the thin film consists essentially of silicon dioxide.
6. The process of claim 1 , wherein the thin film is a multicomponent oxide thin film comprising silicon dioxide and one or more additional oxides.
7. The process of claim 6 , wherein the additional oxide is selected from the group consisting of zirconium oxide, titanium oxide, hafnium oxide, tantalum oxide, aluminum oxide, yttrium oxide and lanthanum oxide.
8. The process of claim 7 , wherein the additional oxide is produced by contacting the substrate with a halide compound selected from the group consisting of vaporized halide compounds of zirconium, aluminum, titanium, hafnium, and tantalum, such that the halide compound bonds to the substrate and converting the bonded halide compound into an oxide by contacting it with a vaporized reactive oxygen source compound.
9. The process of claim 1 , wherein the silicon compound is selected from the group consisting of silicon compounds of the formula:
Si y NH y−1 L 2y+2 ,
wherein y is an integer from 2 to 4,
each L can independently be F, Cl, Br, I, alkyl, aryl, alkoxy, vinyl (—CH═CH 2 ), cyano (—CN), amino, silyl (H 3 Si—), alkylsilyl, alkoxysilyl, silylene or alkylsiloxane, and wherein the alkyl and alkoxy groups can be linear or branched and contain at least one substituent, with the proviso that at least one L is an organic ligand.
10. An atomic layer deposition (ALD) process for forming silicon dioxide on a substrate in a reaction space comprising:
contacting the substrate with a first reactant comprising silicon and selected from the group consisting of amino substituted silanes and silazanes, wherein the first reactant comprises at least one organic ligand;
removing any excess first reactant;
contacting the substrate with a second reactant comprising an oxygen radical, or a hydroxyl radical; and
removing any excess second reactant and reaction by-products; wherein when contacting the substrate the reactant flows continuously from an inlet of the reaction space to an outlet of the reaction space.
11. The process of claim 10 , wherein the first reactant comprising silicon and the second reactant comprising an oxygen radical, or a hydroxyl radical are the only reactants used to form the silicon dioxide.