Method for depositing silicon-free carbon-containing film as gap-fill layer by pulse plasma-assisted deposition
A Si-free C-containing film having filling capability is deposited by forming a viscous polymer in a gas phase by striking an Ar, He, or N 2 plasma in a chamber filled with a volatile hydrocarbon precursor that can be polymerized within certain parameter ranges which define mainly partial pressure of precursor during a plasma strike, and wafer temperature.
1. A method of filling a patterned recess on a surface of a substrate, the method comprising the steps of:
providing a substrate comprising a recess in a reaction space;
providing a silicon-free carbon-containing precursor to the reaction space, thereby filling the recesses with a gas phase precursor; and
after providing the silicon-free carbon-containing precursor to the reaction space, providing a plasma to the reaction space, thereby forming a viscous material in the recess,
wherein the viscous material flows in the recess and accumulates at a bottom of the recess to thereby form deposited material at the bottom of the recess,
wherein the deposited material solidifies,
wherein the step of providing the plasma comprises striking the plasma, and
wherein step the step of providing the plasma is conducted intermittently in a manner of pulsing the plasma on and off.
2. The method according to claim 1 , wherein the precursor is provided with a precursor flow as a portion of a total gas flow to the reaction space in a range of about 10% to about 100%.
3. The method according to claim 1 , wherein a partial pressure of the precursor in the reaction space is greater than 200 Pa.
4. The method according to claim 1 , wherein a temperature of the substrate is between about 50° C. to about 150° C.
5. The method according to claim 1 , wherein a total pressure within the reaction space is greater than 500 Pa.
6. The method according to claim 1 , wherein the precursor is polymerized using the plasma.
7. The method according to claim 6 , wherein an average chain length of the viscous material is greater than ten times an average chain length of a molecule of the precursor.
8. The method according to claim 1 , wherein the precursor comprises an unsaturated hydrocarbon.
9. The method according to claim 8 , wherein the precursor comprises one or more of unsaturated or cyclic hydrocarbon having a vapor pressure of 1,000 Pa or more at 25° C.
10. The method according to claim 1 , wherein the precursor comprises one or more compounds selected from the group consisting of C2-C8 alkynes (C n H 2n−2 ), C2-C8 alkenes (C n H 2n ), C2-C8 diene (C n H n+2 ), C3-C8 cycloalkenes, C3-C8 annulenes (C n H n ), C3-C8 cycloalkanes, and substituted hydrocarbons of the foregoing.
11. The method according to claim 1 , wherein the precursor comprises cyclopentene.
12. The method according to claim 1 , wherein the recess has a width and a depth with an aspect ratio of about 2 to about 10.
13. The method according to claim 1 , wherein the viscous material is liquid.
14. The method according to claim 1 , wherein a plasma power during the step of providing a plasma to the reaction space is greater than 200 W.
15. The method of claim 1 , wherein the step of striking the plasma comprises striking an argon or a helium plasma.
16. The method of claim 1 , further comprising a purge step after the step of providing the silicon-free carbon-containing precursor and before the step of striking the plasma.