Method of filling a gap

Abstract

A method for filling a gap in a substrate is disclosed. The method includes providing a substrate having a gap in a reaction chamber, forming a first reactive species from a first reactant to create an inhibiting layer near a top of the gap, and performing one or more deposition cycles to deposit material into the gap. Each deposition cycle includes introducing a second reactant to form a chemisorbed layer, and generating a second reactive species from a third reactant using pulsed plasma power, which reacts with the chemisorbed layer to form a deposited layer. The inhibiting layer partially inhibits deposition at the top of the gap. The deposited material includes silicon nitride, which is subsequently converted to silicon oxide by providing a fourth reactant including hydrogen and oxygen. This conversion results in volume expansion and improved gap filling.

Description

Technical Field

[0001] This disclosure generally relates to filling gaps in a substrate. More specifically, this disclosure relates to filling gaps with silicon oxide (SiO2). Background Technology

[0002] Semiconductor manufacturing processes used to form semiconductor device structures (such as transistors, memory elements, and integrated circuits) are broad and can include deposition processes. Deposition processes can fill gaps in a substrate.

[0003] Structures on the substrate may include gaps, which may be hollow features accessible via openings in the substrate surface. If a deposited layer also needs to be deposited within the hollow feature via openings to fill the gaps, the deposition process of the silicon oxide layer on the substrate may become challenging.

[0004] Therefore, a silicon oxide deposition process is needed that can fill the gaps in the substrate. Summary of the Invention

[0005] This synopsis is provided to introduce some concepts in a simplified form. These concepts are further described in detail in the following detailed description of exemplary embodiments of this disclosure. This synopsis is not intended to identify key or essential features of the claimed subject matter, nor is it intended to limit the scope of the claimed subject matter.

[0006] In at least one embodiment of the invention, a method for filling a gap is provided. The method may include: providing a substrate having a gap in a reaction chamber; forming a first active material from a first reactant to form a suppression layer near the top of the gap. The method may further include performing one or more deposition cycles to deposit material into the gap, wherein each deposition cycle includes: introducing a second reactant into the reaction chamber, wherein the second reactant reacts with the surface of the substrate to form a chemisorption layer in the gap; and forming a second active material from a third reactant, which reacts with the chemisorption layer to form a deposited layer, wherein the second active material is formed by providing pulsed plasma power to electrodes for a continuous plasma power cycle to form plasma in the reaction chamber, wherein the reaction of the second reactant near the top of the gap is at least partially suppressed by the suppression layer, and the deposited material comprises silicon nitride. A fourth reactant comprising hydrogen and oxygen may be provided to convert silicon nitride into silicon oxide.

[0007] In at least one embodiment of the present invention, the fourth reactant comprises one or more molecules selected from water and hydrogen peroxide.

[0008] In at least one embodiment of the invention, a fourth reactant is provided to convert silicon nitride into silicon oxide, causing the volume of the deposited material to expand between 20% and 70%.

[0009] For the purpose of summarizing the invention and its advantages relative to the prior art, certain objects and advantages of the invention have been described above. It should be understood, of course, that not all of these objects or advantages may necessarily be achieved according to any particular embodiment of the invention. Therefore, for example, those skilled in the art will recognize that the invention may be embodied or implemented in a manner that achieves or optimizes one or more advantages taught or suggested herein, without necessarily achieving other objects or advantages that may be taught or suggested herein.

[0010] All these embodiments are intended to fall within the scope of the invention disclosed herein. These and other embodiments will be readily apparent to those skilled in the art from the following detailed description of certain embodiments with reference to the accompanying drawings. The invention is not limited to any particular embodiment disclosed. Attached Figure Description

[0011] Although the specification concludes with claims that specifically point out and clearly claim protection for what are considered embodiments of the invention, the advantages of the embodiments of this disclosure can be more readily determined from the description of certain examples of embodiments of this disclosure when read in conjunction with the accompanying drawings, wherein:

[0012] Figure 1 A non-limiting exemplary process flow is shown, illustrating a method of filling gaps in a substrate with silicon oxide.

[0013] Figure 2a and Figure 2b It shows that it can be used Figure 1 The structural formula of the second reactant in the method.

[0014] Figure 3 Depicting the use Figure 1 Methods and sources Figure 2a The cross-section of the gap filled by the second reactant.

[0015] The illustrations presented herein are not intended to be actual views of any particular material, structure, or device, but are merely idealized representations used to describe embodiments of this disclosure. Detailed Implementation

[0016] Although certain embodiments and examples are disclosed below, those skilled in the art will understand that the invention extends beyond the specific embodiments and / or uses disclosed herein, as well as their obvious modifications and equivalents. Therefore, it is intended that the scope of the disclosed invention should not be limited to the specific embodiments described below.

[0017] As used herein, the term “substrate” can refer to any one or more underlying materials on which devices, circuits or layers can be formed.

[0018] As used herein, the term “cyclic chemical vapor deposition” can refer to any process in which a substrate is sequentially exposed to one or more volatile precursors, which react and / or decompose on the substrate to produce the desired deposition.

[0019] As used herein, the term plasma can refer to a state of matter characterized by the presence of a large number of charged particles in any combination of ions or electrons. Plasma can be used to generate reactive substances from reactants.

[0020] As used herein, the term reactant may refer to a gas containing silicon, phosphorus, hydrogen, oxygen or nitrogen, or any mixture thereof.

[0021] As used herein, the term "atomic layer deposition" (ALD) can refer to a vapor-phase deposition process in which deposition cycles, preferably multiple consecutive cycles, are performed in a reaction chamber. Typically, during each cycle, a precursor is chemisorbed onto the deposition surface (e.g., a substrate surface or a previously deposited lower layer surface, such as material from a previous ALD cycle), forming a monolayer or sub-monolayer that is not readily reactive with another precursor (i.e., a self-limiting reaction). Subsequently, if desired, a reactant (e.g., another precursor or reactive gas) can be introduced into a processing chamber to convert the chemisorbed precursor into the desired material on the deposition surface. Typically, this reactant is capable of further reacting with the precursor. Furthermore, a purging step can be used during each cycle to remove excess precursor from the processing chamber and / or excess reactant and / or reaction byproducts from the processing chamber after the conversion of the chemisorbed precursor. Furthermore, as used herein, the term “atomic layer deposition” is also intended to include processes specified by related terms such as “chemical vapor deposition,” “atomic layer epitaxy” (ALE), molecular beam epitaxy (MBE), gas-source MBE or organometallic MBE, and chemical beam epitaxy when performed with alternating pulses of a precursor composition, a reactive gas, and a purge gas (e.g., an inert carrier gas).

[0022] As used herein, the terms “layer” and “thin layer” can refer to any continuous or discontinuous structure and material formed by the methods disclosed herein. For example, “layer” and “thin layer” can include 2D materials, nanolaminated materials, nanorods, nanotubes, or nanoparticles, or even partially or entirely molecular layers, or partially or entirely atomic layers or atomic and / or molecular clusters. “Layer” and “thin layer” can include materials or layers with pinholes, but still at least partially continuous.

[0023] Numerous exemplary materials are provided throughout the embodiments of this disclosure. It should be noted that the chemical formulas given for each material should not be construed as limiting, and the non-limiting exemplary materials given should not be limited by the given exemplary stoichiometry.

[0024] Figure 1A method 100 for filling gaps in a substrate with silicon oxide is illustrated. In at least one embodiment of the invention, the method may include: providing a substrate 110 having gaps in a reaction chamber, and forming a first active material from a first reactant to form a suppression layer 120 near the top of the gap. The suppression layer at the top of the gap can substantially block any subsequent deposition steps.

[0025] Method 100 may further include performing one or more deposition cycles to deposit material into the gap, wherein each deposition cycle includes: introducing a second reactant into a reaction chamber 130, wherein the second reactant reacts with a substrate surface to form a chemisorption layer at a location in the gap where there is no suppression layer, and forming a second active material 140 by a third reactant, the second active material reacting with the chemisorption layer to form a deposited layer. The second active material is formed by providing pulsed plasma power to the electrodes for a continuous plasma power cycle to form plasma in the reaction chamber. The reaction of the second reactant near the top of the gap is at least partially suppressed by the suppression layer, and the deposited material comprises phosphorus-doped silicon nitride.

[0026] In some embodiments, deposition cycle 135 can be repeated until sufficient material is provided in the gap or the inhibition layer becomes inactive. If the inhibition layer becomes inactive, it can be renewed via step 145. For example, the inhibition layer can be renewed every 1 to 33 deposition cycles. Thereafter, the method can perform deposition cycle 135. Similarly, these steps 145 can be repeated.

[0027] A fourth reactant 150, comprising hydrogen and oxygen, is provided to convert silicon nitride into silicon oxide. The fourth reactant contains one or more molecules selected from water and hydrogen peroxide. The conversion of silicon nitride into silicon oxide causes the volume of the deposited material to expand between 20% and 70%, which helps fill interstitial spaces. The conversion makes the material flowable, allowing it to flow to the bottom of the interstitial spaces, which also helps fill them.

[0028] The fourth reactant can be provided 1 to 3 times. The fourth reactant can be provided in a separate tool or reaction chamber, such as a vertical furnace, and the method may include transferring the substrate from the reaction chamber to the vertical furnace. The fourth reactant can be provided by providing oxygen and hydrogen and igniting them to form water. The substrate can be heated to 100°C to 500°C while the fourth reactant is being provided. Water can be provided during steam annealing to convert silicon nitrite to silicon oxide.

[0029] In at least one embodiment of the invention, the substrate may include a gap, which is a hollow feature accessible via an opening in the substrate surface.

[0030] In at least one embodiment, the plasma can be a continuous-wave plasma. Continuous-wave plasma can possess the correct properties for activating reactants.

[0031] In at least one embodiment, the deposited material includes phosphorus. Phosphorus enables the conversion of SiON:P to SiO:P. For phosphorus (P), if the quality of SiN is good, the conversion will occur at a temperature between 100-500°C. A phosphorus content of 5% may be the minimum required for the deposited SiON:P. In some embodiments, the conversion can be carried out by converting phosphorus to phosphoric acid during H2O exposure. Phosphoric acid then converts SiN to SiO, releasing NH3.

[0032] In at least one embodiment, the method includes introducing a fifth reactant containing phosphorus.

[0033] In at least one embodiment, the second reactant may comprise phosphorus that may ultimately be present in the deposited material. The second reactant may comprise phosphite or phosphate.

[0034] In at least one embodiment, the second reactant may comprise a methyl group. The second reactant may comprise a methylsilyl group. The second reactant may comprise a trimethylsilyl group. The second reactant may comprise three trimethylsilyl groups.

[0035] In at least one embodiment, the second reactant comprises oxygen or silicon.

[0036] In at least one embodiment, the second reactant comprises tris(trimethylsilyl)phosphite.

[0037] In at least one embodiment, the second reactant comprises tris(trimethylsilyl)phosphate.

[0038] In at least one embodiment, the deposited material includes oxygen.

[0039] In at least one embodiment, the third reactant comprises nitrogen. The nitrogen may be molecular nitrogen (N2).

[0040] In at least one embodiment, the first reactant may comprise nitrogen. The first reactant may be selected from one or more of the following: fluorine nitride (NF3), ammonia (NH3), diazine (N2H2), hydrogen (H2), or nitrogen (N2). A good inhibitory layer may be made of fluorine nitride (NF3), ammonia (NH3), diazine (N2H2), hydrogen (H2), or nitrogen (N2).

[0041] Figure 2a and Figure 2b It shows that it can be used Figure 1 The structural formula of the second reactant in the method. Figure 2a Tris(trimethylsilyl)phosphite was disclosed. Figure 2bTris(trimethylsilyl) phosphate was disclosed.

[0042] Figure 3 Publicly available Figure 1 Methods and sources Figure 2a An image showing the second reactant filling the gap. This image illustrates that the gap is well filled along its length using the method disclosed herein.

[0043] The exemplary embodiments described above do not limit the scope of the invention, as these embodiments are merely examples of embodiments of the invention, the scope of which is defined by the appended claims and their legal equivalents. Any equivalent embodiments are intended to fall within the scope of the invention. In fact, various modifications to this disclosure, such as alternative useful combinations of the described elements, in addition to those shown and described herein, will become apparent to those skilled in the art from the description. These modifications and embodiments are also intended to fall within the scope of the appended claims.

Claims

1. A method for filling a gap, the method comprising the following steps: A substrate with gaps is provided in the reaction chamber; A first active substance is formed from the first reactant, which is used to form an inhibitory layer near the top of the gap; as well as Perform one or more deposition cycles to deposit material into the gaps, wherein each deposition cycle includes: A second reactant is introduced into the reaction chamber, wherein the second reactant reacts with the surface of the substrate to form a chemisorption layer in the gap; and The third reactant forms a second active substance, which reacts with the chemisorption layer to form a deposition layer. Specifically, the second active material is formed by providing pulsed plasma power to the electrodes and maintaining continuous plasma power for a period of time to create plasma in the reaction chamber. In this process, the reaction of the second reactant near the top of the gap is at least partially suppressed by the suppression layer, and the deposited material includes silicon nitride, wherein a fourth reactant comprising hydrogen and oxygen is provided to convert the silicon nitride into silicon oxide.

2. The method according to claim 1, wherein, The fourth reactant includes one or more molecules selected from water and hydrogen peroxide.

3. The method according to claim 1, wherein, A fourth reactant is provided to convert silicon nitride into silicon oxide, causing the volume of the deposited material to expand between 20% and 70%.

4. The method according to claim 1, wherein, The inhibition layer is formed every 1 to 33 deposition cycles.

5. The method according to claim 1, wherein, Provide the fourth reactant and repeat 1 to 3 times.

6. The method according to claim 1, wherein, The fourth reactant is provided in a vertical furnace, and the method includes transferring a substrate from a reaction chamber to a vertical furnace.

7. The method according to claim 1, wherein, The fourth reactant is provided by supplying oxygen and hydrogen and igniting them to form water.

8. The method according to claim 1, wherein, The substrate is heated to 100°C to 500°C, and water is provided during steam annealing to convert silicon nitrite into silicon oxide.

9. The method according to claim 1, wherein, The second reactant contains phosphorus.

10. The method according to claim 9, wherein, The method includes introducing a fifth reactant containing phosphorus.

11. The method according to claim 9, wherein, The second reactant contains a methyl group.

12. The method according to claim 11, wherein, The second reactant contains methylsilyl groups.

13. The method according to claim 12, wherein, The second reactant contains at least one trimethylsilyl group.

14. The method according to claim 9, wherein, The second reactant contains oxygen.

15. The method according to claim 9, wherein, The second reactant contains silicon.

16. The method according to claim 9, wherein, The second reactant contains tris(trimethylsilyl)phosphite.

17. The method according to claim 9, wherein, The second reactant contains tris(trimethylsilyl) phosphate.

18. The method according to claim 1, wherein, The deposited material includes oxygen.

19. The method according to claim 1, wherein, The third reactant contains nitrogen.

20. The method according to claim 1, wherein, The first reactant contains nitrogen.

21. The method according to claim 1, wherein, The first reactant is selected from one or more of the following: nitrogen fluorine (NF3), ammonia (NH3), diazine (N2H2), hydrogen (H2) or nitrogen (N2).

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