Surface preparation prior to deposition
View Patent ↗Methods are provided herein for treating substrate surfaces in preparation for subsequent nucleation-sensitive depositions (e.g., polysilicon or poly-SiGe) and adsorption-driven deposition (e.g. atomic layer deposition or ALD). Prior to depositing, the surface is treated with non-depositing plasma products. The treated surface more readily nucleates polysilicon and poly-SiGe (such as for a gate electrode), or more readily adsorbs ALD reactants (such as for a gate dielectric). The surface treatment provides surface moieties more readily susceptible to a subsequent deposition reaction, or more readily susceptible to further surface treatment prior to deposition. By changing the surface termination of the substrate with a low temperature radical treatment, subsequent deposition is advantageously facilitated without depositing a layer of any appreciable thickness and without significantly affecting the bulk properties of the underlying material. Preferably less than 10 Å of the bulk material incorporates the excited species, which can include fluorine, chlorine and particularly nitrogen excited species.
1. A method of depositing a film on a semiconductor surface in a partially fabricated integrated circuit, the method comprising:
exposing the surface to products of a plasma, thereby modifying termination of the semiconductor surface without significantly affecting bulk properties beneath the surface; and
after modifying the surface termination, depositing a layer thereover using an atomic layer deposition process;
wherein exposing incorporates less than 1 atomic % of the products of the plasma at a depth of greater than about 10 Å from the surface.
2. The method of claim 1 , wherein the plasma comprises a nitrogen excited species.
3. The method of claim 1 , wherein the atomic layer deposition comprises depositing an oxide having a higher dielectric constant than silicon nitride.
4. The method of claim 3 , wherein the oxide is selected form the group consisting of aluminum oxide, zirconium oxide, hafnium oxide, barium strontium titanate and strontium bismuth tantalate.
5. The method of claim 1 , wherein the plasma is generated remote from the surface.
6. A method of depositing a film on a surface of a semiconductive material in a partially fabricated integrated circuit, the method comprising:
exposing the surface to products of a plasma, thereby modifying termination of the semiconductive surface without significantly affecting bulk properties beneath the surface; and
after modifying the surface termination, depositing a layer thereover using an atomic layer deposition process;
wherein the atomic layer deposition process comprises a metal oxide deposition; and wherein exposing incorporates less than 1 atomic % of the products of the plasma at a depth of greater than about 10 Å from the surface.
7. A method of depositing a film on a surface of a semiconductive material in a partially fabricated integrated circuit, the method comprising:
exposing the surface to products of a plasma, thereby modifying termination of the semiconductive surface without significantly affecting bulk properties beneath the surface; and
after modifying the surface termination, depositing a layer thereover using an atomic layer deposition process;
wherein the atomic layer deposition process comprises two reactant pulses with intervening purge pulses in each cycle; and wherein exposing incorporates less than 1 atomic % of the products of the plasma at a depth of greater than about 10Å from the surface.
8. A method of depositing a film on a surface of a semiconductive material in a partially fabricated integrated circuit, the method comprising:
exposing the surface to products of a plasma, thereby modifying termination of the semiconductive surface without depositing greater than one atomic monolayer of the products of the plasma on the surface; and
after modifying the surface termination, depositing a layer thereover using an atomic layer deposition process;
wherein the atomic layer deposition process comprises a metal oxide deposition.
9. A method of depositing a film on a surface of a semiconductive material in a partially fabricated integrated circuit, the method comprising:
exposing the surface to products of a plasma, thereby modifying termination of the semiconductive surface without depositing greater than one atomic monolayer of the products of the plasma on the surface; and
after modifying the surface termination, depositing a layer thereover using an atomic layer deposition process;
wherein the atomic layer deposition process comprises two reactant pulses with intervening purge pulses in each cycle.
10. The method of claim 9 , wherein the plasma comprises a nitrogen excited species.
11. The method of claim 9 , wherein the atomic layer deposition comprises depositing an oxide having a higher dielectric constant than silicon nitride.
12. The method of claim 11 , wherein the oxide is selected form the group consisting of aluminum oxide, zirconium oxide, hafnium oxide, barium strontium titanate and strontium bismuth tantalate.
13. The method of claim 9 , wherein the plasma is generated remote from the surface.