Flowable dielectric using oxide liner
Methods of forming silicon oxide layers are described. The methods include mixing a carbon-free silicon-containing precursor with a radical-nitrogen precursor, and depositing a silicon-and-nitrogen-containing layer on a substrate. The radical-nitrogen precursor is formed in a plasma by flowing a hydrogen-and-nitrogen-containing precursor into the plasma. Prior to depositing the silicon-and-nitrogen-containing layer, a silicon oxide liner layer is formed to improve adhesion, smoothness and flowability of the silicon-and-nitrogen-containing layer. The silicon-and-nitrogen-containing layer may be converted to a silicon-and-oxygen-containing layer by curing and annealing the film. Methods also include forming a silicon oxide liner layer before applying a spin-on silicon-containing material.
1. A method of forming a flowable dielectric layer on a substrate, the method comprising the sequential steps of:
forming a generally conformal silicon oxide liner layer on silicon nitride on the substrate by exposing the substrate to a silicon-containing liner precursor and an oxygen-containing liner precursor, wherein the substrate is maintained at a liner deposition temperature;
forming a carbon-free flowable silicon-nitrogen-and-hydrogen-containing layer on the silicon oxide liner layer using radical-component chemical vapor deposition, wherein the substrate is maintained at a bulk deposition temperature, wherein the bulk-deposition temperature is less than 120° C.;
curing the substrate at a substrate temperature below or about 400° C. in an ozone-containing atmosphere, and
raising a temperature of the substrate to an oxygen anneal temperature above or about 600° C. in an oxygen-containing atmosphere.
2. The method of claim 1 wherein forming the carbon-free flowable silicon-nitrogen-and-hydrogen-containing layer comprises:
flowing a nitrogen-and-hydrogen-containing gas into a plasma region to produce a radical-nitrogen precursor;
combining a carbon-free silicon-containing precursor with the radical-nitrogen precursor in a plasma-free substrate processing region; and
depositing a silicon-and-nitrogen-containing layer on the substrate.
3. The method of claim 2 wherein the nitrogen-and-hydrogen-containing gas comprises ammonia (NH 3 ).
4. The method of claim 2 wherein the nitrogen-and-hydrogen-containing gas comprises at least one of nitrogen (N 2 ), hydrogen (H 2 ), hydrazine (N 2 H 4 ) and ammonia (NH 3 ).
5. The method of claim 1 wherein a thickness of the generally conformal silicon oxide liner is less than or about 100 Å.
6. The method of claim 2 wherein the carbon-free silicon-containing precursor comprises N(SiH 3 ) 3 .
7. The method of claim 1 wherein the carbon-free flowable silicon-nitrogen-and-hydrogen-containing layer comprises a carbon-free Si—N—H layer.
8. The method of claim 1 wherein the bulk-deposition temperature is lower than the liner deposition temperature.
9. The method of claim 1 wherein the oxygen-containing liner precursor comprises oxygen (O 2 ).
10. The method of claim 1 wherein the liner deposition temperature is greater than 400° C.
11. The method of claim 1 wherein the silicon-containing liner precursor comprises TEOS.
12. The method of claim 1 wherein the oxygen-containing atmosphere comprises one or more gases selected from the group consisting of atomic oxygen, ozone, and steam (H 2 O).
13. The method of claim 2 wherein the plasma region is in a remote plasma system.
14. The method of claim 2 wherein the plasma region is a partitioned portion of the substrate processing chamber separated from the plasma-free substrate processing region by a showerhead.
15. The method of claim 1 wherein the oxygen-containing liner precursor comprises ozone.