Method and apparatus for filling gap using atomic layer deposition
A method and an apparatus for filling a gap by using an atomic layer deposition (ALD) method are provided. The method includes forming a first reaction inhibition layer on a side wall of the gap; forming a first precursor layer by adsorbing a first reactant into a bottom of the gap and the side wall of the gap around the bottom of the gap; and forming a first atomic layer on the bottom of the gap and the side wall of the gap around the bottom of the gap by adsorbing a second reactant into the first precursor layer. The forming of the first reaction inhibition layer may include adsorbing a first reaction inhibitor into the side wall of the gap; and forming a second reaction inhibitor by removing a specific ligand from the first reaction inhibitor.
1. A method of filling a gap formed on a substrate, the method comprising:
forming a first reaction inhibition layer on a side wall of the gap;
forming a first precursor layer by adsorbing a first reactant into a bottom of the gap and into the side wall of the gap around the bottom of the gap; and
forming a first atomic layer on the bottom of the gap and the side wall of the gap around the bottom of the gap by adsorbing a second reactant into the first precursor layer,
wherein the forming of the first reaction inhibition layer comprises,
adsorbing a first reaction inhibitor into the side wall of the gap, and
forming a second reaction inhibitor by removing a specific ligand from the first reaction inhibitor,
wherein the first reaction inhibitor is adsorbed to have a density gradient in which a density of the first reaction inhibitor decreases toward the bottom of the gap, and
the second reaction inhibitor comprises a precursor material that does not react with the second reactant.
2. The method of claim 1 ,
wherein the second reaction inhibitor is formed by removing at least a part of a ligand having an adsorption characteristic from the first reaction inhibitor by using a specific gas.
3. The method of claim 2 ,
wherein the second reaction inhibitor has a greater adsorption density than that of the first reaction inhibitor.
4. The method of claim 1 ,
wherein the density gradient of the first reaction inhibitor is determined based on equation
1
=
4
w
3
(
1
+
3
8
(
Pt
S
2
π
mkT
)
-
1
)
wherein, denotes a depth in nm at a location of the side wall of the gap into which the first reaction inhibitor is adsorbed, w denotes a width in nm of the gap, P denotes a partial pressure Pa of the first reaction inhibitor in a reaction chamber, t denotes an exposure time s of the first reaction inhibitor, S denotes a saturation dose (≈2.5×10 18 molecules·meter), m denotes a molecular mass in kg of the first reaction inhibitor, k denotes a Boltzmann factor equal to 1.38×10 −23 Joules/Kelvin, and T denotes a temperature in the reaction chamber measured in Kelvins.
5. The method of claim 1 ,
wherein the first reaction inhibitor comprises a center metal and an organic ligand.
6. The method of claim 1 ,
wherein the second reaction inhibitor is oxidized by at least one of ozone (O 3 ) or oxygen (O 2 ) plasma.
7. The method of claim 1 ,
wherein the second reaction inhibitor does not react with water (H 2 O) and does not react with oxygen (O 2 ).
8. The method of claim 1 , further comprising:
forming a first filling layer by repeatedly performing the forming of the first precursor layer and the forming of the first atomic layer for a plurality of cycles.
9. The method of claim 8 ,
wherein a density of the first reaction inhibitor decreases toward the bottom of the gap so that the first filling layer is formed from the bottom of the gap in a bottom-up direction.
10. The method of claim 8 , further comprising:
after forming the first filling layer, forming a second reaction inhibition layer on the side wall of the gap;
forming a second precursor layer on an upper surface of the first filling layer and the side wall of the gap around the upper surface of the first filling layer; and
forming a second atomic layer on the upper surface of the first filling layer and the side wall of the gap around the upper surface of the first filling layer.
11. The method of claim 10 , further comprising:
forming a second filling layer from the upper surface of the first filling layer in a bottom-up direction by repeatedly performing the forming of the second precursor layer and the forming of the second atomic layer for the plurality of cycles.
12. The method of claim 1 , further comprising:
before forming the first reaction inhibition layer on the side wall of the gap, forming an upper atomic layer on a surface of the substrate around an entrance of the gap.
13. A method of filling a gap formed on a substrate, the method comprising:
forming a first filling layer by sequentially adsorbing first and second reactants into a side wall and a bottom of the gap;
forming a first reaction inhibition layer on the first filling layer formed on the side wall of the gap;
forming a first precursor layer by adsorbing the first reactant into the first filling layer formed on the bottom of the gap and around the bottom of the gap; and
forming a first atomic layer on the first filling layer formed on the bottom of the gap and around the bottom of the gap by adsorbing the second reactant into the first precursor layer,
wherein the forming of the first reaction inhibition layer comprises,
adsorbing a first reaction inhibitor into the side wall of the gap, and
forming a second reaction inhibitor by removing a specific ligand from the first reaction inhibitor,
wherein the first reaction inhibitor is adsorbed to have a density gradient in which a density of the first reaction inhibitor decreases toward the bottom of the gap, and
the second reaction inhibitor comprises a precursor material that does not react with the second reactant.
14. The method of claim 13 , further comprising forming:
a second filling layer from an upper surface of the first filling layer in a bottom-up direction by repeatedly performing the forming of the first precursor layer and the forming of the first atomic layer for a plurality of cycles.