Methods for depositing a film on a surface of a substrate by cyclical deposition methods including pulsed purge processes
Methods for depositing a film on a surface of substrate by cyclical deposition methods including pulsed purge processed are disclosed. The pulsed purge processes include introducing a purge gas into a reaction chamber at a first flow rate, and introducing a purge gas into the reaction chamber at second flow rate, the first flow rate being different to the second flow rate.
1 . A method for depositing a film on a substrate, the method comprising:
seating a substrate within a reaction chamber;
sequentially and alternatingly contacting the substrate with a plurality of pulsed reactant flows of at least a first reactant and a second reactant; and
performing multiple cycles of a pulsed purge process between selected pulsed reactant flows to introduce a purge gas into the reaction chamber, wherein a cycle of the multiple cycles of the pulsed purge process comprises switching between:
introducing the purge gas into the reaction chamber at a first flow rate; and
introducing the purge gas into the reaction chamber at a second flow rate, wherein the first flow rate is different to the second flow rate.
2 . The method of claim 1 , wherein the first flow rate is greater than the second flow rate.
3 . The method of claim 1 , wherein the second flow rate is zero, such that introduction of the purge gas into the reaction chamber is ceased during the introducing the purge gas into the reaction chamber at the second flow rate.
4 . The method of claim 1 , wherein the pulsed purge process further comprises, sequentially and alternately increasing and decreasing a pressure within the reaction chamber.
5 . The method of claim 1 , wherein the performing multiple cycles of the pulsed purge process further comprises, flowing the purge gas at the first flow rate into the reaction chamber through a first gas flow path, and flowing the purge gas at the second flow rate into the reaction chamber through a second gas flow path.
6 . The method of claim 5 , wherein the flowing the purge gas into the reaction chamber is sequentially and alternately switched between the first gas flow path and the second gas flow path.
7 . The method of claim 5 , wherein a fluidic circuit fluidically connecting a purge gas source to the reaction chamber comprises a low-flow channel and a high-flow channel.
8 . The method of claim 7 , wherein the first gas flow path comprises both the low-flow channel and the high-flow channel and is configured to deliver the purge gas to the reaction chamber at the first flow rate.
9 . The method of claim 8 , wherein the second gas flow path comprises the low-flow channel, but not the high-flow channel, and is configured to deliver the purge gas to the reaction chamber at the second flow rate, wherein the first flow rate is greater than the second flow rate.
10 . The method of claim 2 , wherein switching the purge gas flow between the first flow rate and the second flow rate comprises closing a valve disposed along the high-flow channel.
11 . The method of claim 10 , wherein switching the purge gas flow between the second flow rate and the first flow rate comprises opening the valve disposed along the high-flow channel.
12 . The method of claim 7 , wherein flowing the purge gas at the first flow rate further comprises, flowing the purge gas through both the low-flow channel and the high-flow channel.
13 . The method of claim 10 , wherein flowing the purge gas at the second flow rate further comprises, flowing the purge gas through the low-flow channel and not the high-flow channel.
14 . The method of claim 1 , wherein switching between the first flow rate and the second flow rate is performed in less than 0.1 seconds.
15 . The method of claim 1 , wherein a pulse period for introducing the purge gas into the reaction chamber at the first flow rate is less than 30 seconds.
16 . The method of claim 1 , wherein a pulse period for introducing the purge gas into the reaction chamber at the second flow rate is less than 1 second.
17 . The method of claim 1 , wherein a duty cycle of the pulsed purge process is greater than 1 percent (%).
18 . The method of claim 1 , wherein the second reactant is selected from the group consisting of water vapor (H 2 O), hydrogen peroxide vapor (H 2 O 2 ), ammonia (NH 3 ), hydrogen (H 2 ), ozone (O 3 ), oxygen (O 2 ), and alcohol vapors.
19 . The method of claim 1 , wherein the first reactant has a sticking coefficient less than the second reactant.
20 . The method of claim 1 , wherein the deposited film comprises a conformal aluminum oxide film with a step coverage greater than 95 percent (%).
21 . The method of claim 20 , wherein the conformal aluminum oxide film fills a plurality of non-planar features on the substrate without formation of a seam within the non-planar features.
22 . The method of claim 21 , wherein the plurality of non-planar features comprise a plurality of three-dimensional partially fabricated device structures and the conformal aluminum oxide film covers the plurality of three-dimensional partially fabricated device structures with a step coverage greater than 98 percent (%).
23 . A method of depositing a film on a substrate, the method comprising:
seating a non-planar substrate within a reaction chamber;
depositing a conformal film on a surface of the non-planar substrate by performing one or more deposition cycles of a cyclical deposition process, wherein a unit deposition cycle of the cyclical deposition process comprises:
contacting the substrate with a first vapor phase reactant;
contacting the substrate with a second vapor phase reactant; and
between selected contacting steps, sequentially and alternately switching between a high-flow gas path and a low-flow gas path fluidly connecting a purge gas source to the reaction chamber, thereby cycling the flow rate of the purge gas into the reaction chamber between a first flow rate through the high-flow gas path and a second flow rate through the low-flow gas path, wherein the first flow rate is greater than the second flow rate.
24 . A method of depositing a film on a substrate, the method comprising:
seating a non-planar substrate within a reaction chamber;
contacting the substrate with a plurality of pulsed flows of a reactant at spaced apart time intervals into the reaction chamber to deposit a film on the substrate; and
performing a cyclical purge process to remove excess reactant from the reaction chamber between selected pulsed flows of the plurality of pulsed flows, wherein the cyclical purge process comprises:
increasing the pressure within the reaction chamber by introducing a purge gas into the reaction chamber at a first flow rate through a high-flow gas path;
decreasing the pressure within the reaction chamber by introducing the purge gas into the reaction chamber at a second flow rate though a low-flow gas path, wherein the first flow rate is greater than the second flow rate; and
re-increasing the pressure within the reaction chamber by introducing the purge gas into the reaction chamber at the first flow rate through the high-flow gas path.