US-12618147-B2 - Methods for depositing phosphorus-doped silicon nitride films

Abstract

Methods for depositing hardmask materials and films, and more specifically, for depositing phosphorus-doped, silicon nitride films are provided. A method of depositing a material on a substrate in a processing chamber includes exposing a substrate to a deposition gas in the presence of RF power to deposit a phosphorus-doped, silicon nitride film on the substrate during a plasma-enhanced chemical vapor deposition (PE-CVD) process. The deposition gas contains one or more silicon precursors, one or more nitrogen precursors, one or more phosphorus precursors, and one or more carrier gases. The phosphorus-doped, silicon nitride film has a phosphorus concentration in a range from about 0.1 atomic percent (at %) to about 10 at %.

Inventors

• Kesong HU
• Rana Howlader
• Michael Wenyoung Tsiang
• Xinhai Han
• Hang Yu
• Deenesh Padhi

Assignees

• APPLIED MATERIALS, INC.

Dates

Publication Date

20260505

Application Date

20191014

Claims (20)

1. 1 . A method of depositing a material on a substrate in a processing chamber, comprising: exposing a substrate to a deposition gas in the presence of RF power to deposit a phosphorus-doped, silicon nitride film on the substrate during a plasma-enhanced chemical vapor deposition process, wherein: the deposition gas comprises a silicon precursor, a nitrogen precursor, a phosphorus precursor, and a carrier gas; and the phosphorus-doped, silicon nitride film has a phosphorus concentration in a range from about 0.1 atomic percent (at %) to about 10 at %.
2. 2 . The method of claim 1 , further comprising turning off the RF power while continuing to expose the substrate to the deposition gas.
3. 3 . The method of claim 1 , wherein the plasma-enhanced chemical vapor deposition process is a pulsed plasma process which comprises pulsing the RF power on and off while continuing to expose the substrate to the deposition gas.
4. 4 . The method of claim 1 , wherein the plasma-enhanced chemical vapor deposition process is a continuous plasma process which comprises maintaining the RF power on while continuing to expose the substrate to the deposition gas.
5. 5 . The method of claim 1 , further comprising densifying the phosphorus-doped, silicon nitride film by exposing the substrate to hydrogen while continuing to expose the substrate to the deposition gas.
6. 6 . The method of claim 1 , further comprising densifying the phosphorus-doped, silicon nitride film by sequentially alternating between cycles of the plasma-enhanced chemical vapor deposition process and a nitrogen-plasma process, wherein the nitrogen-plasma process comprises exposing the substrate to a nitrogen plasma while ceasing to expose the substrate to the deposition gas.
7. 7 . The method of claim 1 , wherein the phosphorus concentration is in a range from about 0.5 at % to about 8 at %.
8. 8 . The method of claim 1 , wherein the phosphorus concentration is in a range from about 1 at % to about 6 at %.
9. 9 . The method of claim 1 , wherein the phosphorus-doped, silicon nitride film has a nitrogen concentration in a range from about 40 at % to about 70 at %.
10. 10 . The method of claim 1 , wherein the phosphorus-doped, silicon nitride film has a silicon concentration in a range from about 25 at % to about 55 at %.
11. 11 . The method of claim 1 , wherein the phosphorus precursor comprises phosphine, methylphosphine, ethylphosphine, propylphosphine, butylphosphine, phosphorus oxychloride, trimethylphosphate, triethylphosphate, isomers thereof, or any combination thereof.
12. 12 . The method of claim 1 , wherein the nitrogen precursor comprises ammonia, hydrazine, dimethyl hydrazine, tert-butylhydrazine, phenylhydrazine, 2,2′-azoisobutane, ethylazide, isomers thereof, or any combinations thereof.
13. 13 . The method of claim 1 , wherein the silicon precursor comprises silane, disilane, trisilane, tetrasilane, pentasilane, methylsilane, chlorosilane, dichlorosilane, trichlorosilane, silicon tetrachloride, hexachlorodisilane, or any combinations thereof.
14. 14 . The method of claim 1 , wherein the carrier gas comprises nitrogen (N 2 ), argon, helium, plasma thereof, or any combination thereof.
15. 15 . The method of claim 1 , wherein the phosphorus-doped, silicon nitride film is a hardmask layer or a stop etch layer.
16. 16 . A method of depositing a material on a substrate in a processing chamber, comprising: exposing a substrate to a deposition gas while depositing a phosphorus-doped, silicon nitride film on the substrate during a plasma-enhanced chemical vapor deposition process, wherein: the deposition gas comprises a silicon precursor, a nitrogen precursor, a phosphorus precursor, and a carrier gas; and the phosphorus-doped, silicon nitride film has a phosphorus concentration in a range from about 0.5 atomic percent (at %) to about 8 at %.
17. 17 . The method of claim 16 , wherein the deposition gas comprises phosphine, silane, and ammonia, and wherein the phosphorus concentration is in a range from about 1 at % to about 6 at %.
18. 18 . A method of depositing a material on a substrate in a processing chamber, comprising: exposing a substrate to a deposition gas to deposit a phosphorus-doped, silicon nitride film on the substrate during a plasma-enhanced chemical vapor deposition process, wherein: the deposition gas comprises a silicon precursor, a nitrogen precursor, a phosphorus precursor, and a carrier gas; and the phosphorus-doped, silicon nitride film has a phosphorus concentration in a range from about 0.1 atomic percent (at %) to about 10 at %; ceasing the plasma-enhanced chemical vapor deposition process; then exposing the substrate to a nitrogen plasma to densify the phosphorus-doped, silicon nitride film during a nitrogen-plasma process; ceasing the nitrogen-plasma process; and sequentially repeating cycles of the plasma-enhanced chemical vapor deposition process and the nitrogen-plasma process.
19. 19 . The method of claim 18 , wherein the plasma-enhanced chemical vapor deposition process is a pulsed plasma process which comprises pulsing an RF power on and off while continuing to expose the substrate to the deposition gas.
20. 20 . The method of claim 18 , wherein the plasma-enhanced chemical vapor deposition process is a continuous plasma process which comprises maintaining an RF power on while continuing to expose the substrate to the deposition gas.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application claims benefit to U.S. Appl. No. 62/779,002, filed on Dec. 13, 2018, which is herein incorporated by reference. BACKGROUND Field Embodiments of the present disclosure generally relate to deposition processes, and in particular to vapor deposition processes for depositing silicon nitride films. Description of the Related Art Integrated circuits have evolved into complex devices that can include millions of transistors, capacitors and resistors on a single chip. The evolution of chip designs continually requires faster circuitry and greater circuit density. The demands for faster circuits with greater circuit densities impose corresponding demands on the materials used to fabricate such integrated circuits. In particular, as the dimensions of integrated circuit components are reduced to the sub-micron scale, it is now desirable to use low resistivity conductive materials as well as low dielectric constant insulating materials to obtain suitable electrical performance from such components. The demands for greater integrated circuit densities also impose demands on the process sequences used in the manufacture of integrated circuit components. For example, in process sequences that use conventional photo lithographic techniques, a layer of energy sensitive resist is formed over a stack of material layers disposed on a substrate. The energy sensitive resist layer is exposed to an image of a pattern to form a photoresist mask. Thereafter, the mask pattern is transferred to one or more of the material layers of the stack using an etch process. The chemical etchant used in the etch process is selected to have a greater etch selectivity for the material layers of the stack than for the mask of energy sensitive resist. That is, the chemical etchant etches the one or more layers of the material stack at a rate much faster than the energy sensitive resist. The etch selectivity to the one or more material layers of the stack over the resist prevents the energy sensitive resist from being consumed prior to completion of the pattern transfer. Thus, a highly selective etchant enhances accurate pattern transfer. As the pattern dimensions are reduced, the thickness of the energy sensitive resist must correspondingly be reduced in order to control pattern resolution. Such thin resist layers can be insufficient to mask underlying material layers during the pattern transfer step due to attack by the chemical etchant. An intermediate layer called a hardmask is often used between the energy sensitive resist layer and the underlying material layers to facilitate pattern transfer because of its greater resistance to the chemical etchant. It is desirable to have thin hardmasks that have both high etch selectivity and are easy to remove after the etching process is complete. As critical dimensions decrease, current hardmask materials lack the desired etch selectivity relative to underlying materials and are often difficult to remove. Thus, there is a need for improved methods for depositing hardmask materials and films. SUMMARY OF THE DISCLOSURE Embodiments provide methods for depositing hardmask materials and films, and more specifically, for depositing phosphorus-doped, silicon nitride films. In one or more embodiments, a method of depositing a material on a substrate in a processing chamber includes exposing a substrate to a deposition gas in the presence of RF power to deposit a phosphorus-doped, silicon nitride film on the substrate during a plasma-enhanced chemical vapor deposition (PE-CVD) process. The deposition gas contains one or more silicon precursors, one or more nitrogen precursors, one or more phosphorus precursors, and one or more carrier gases. The phosphorus-doped, silicon nitride film has a phosphorus concentration in a range from about 0.1 atomic percent (at %) to about 10 at %. In some embodiments, a method of depositing a material on a substrate in a processing chamber includes exposing a substrate to a deposition gas while depositing a phosphorus-doped, silicon nitride film on the substrate during a PE-CVD process. The deposition gas contains one or more silicon precursors, one or more nitrogen precursors, one or more phosphorus precursors, and one or more carrier gases. The phosphorus-doped, silicon nitride film has a phosphorus concentration in a range from about 0.5 at % to about 8 at %. In other embodiments, a method of depositing a material on a substrate in a processing chamber includes exposing a substrate to a deposition gas to deposit a phosphorus-doped, silicon nitride film on the substrate during a PE-CVD process, where the deposition gas contains one or more silicon precursors, one or more nitrogen precursors, one or more phosphorus precursors, and one or more carrier gases and the phosphorus-doped, silicon nitride film has a phosphorus concentration in a range from about 0.1 at % to about 10 at %. The method also includes ceasing the PE-CVD p