KR-102960910-B1 - Method and apparatus for filling gap using atomic layer deposition

Abstract

A gap filling method and apparatus using atomic layer deposition are disclosed. The disclosed gap filling method comprises the steps of: forming a first reaction inhibitor film on the sidewall of a gap; forming a first precursor film by adsorbing a first reactant on the bottom of the gap and the sidewall surrounding it; and forming a first atomic film on the bottom of the gap and the sidewall surrounding it by adsorbing a second reactant on the first precursor film. Herein, the step of forming the first reaction inhibitor film comprises the steps of: adsorbing a first reaction inhibitor on the sidewall of the gap; and forming a second reaction inhibitor by removing a specific ligand of the first reaction inhibitor. The first reaction inhibitor is adsorbed to have a density gradient in which the density decreases toward the bottom of the gap, and the second reaction inhibitor comprises a precursor material that does not react with the second reactant.

Inventors

• 조은형
• 이성희
• 이정엽
• 이한보람

Assignees

• 삼성전자주식회사
• 인천대학교 산학협력단

Dates

Publication Date

20260507

Application Date

20211018

Priority Date

20210908

Claims (20)

1. A method for filling a gap formed in a substrate using atomic layer deposition (ALD), A step of forming a first reaction inhibitory film on the sidewall of the gap; A step of forming a first precursor film by adsorbing a first reactant onto the bottom of the gap and the sidewall of the gap adjacent to the bottom of the gap; and The method includes the step of adsorbing a second reactant onto the first precursor film to form a first atomic film on the bottom of the gap and on the sidewall of the gap adjacent to the bottom of the gap. The step of forming the first reaction inhibition film is, A step of adsorbing a first reaction inhibitor to the sidewall of the gap; and The method comprises the step of forming a second reaction inhibitor by removing a specific ligand of the first reaction inhibitor; The first reaction inhibitor is adsorbed to have a density gradient in which the density decreases toward the bottom of the gap, and A gap filling method comprising a precursor material that does not react with the second reactant, wherein the second reaction inhibitor is the above-mentioned second reaction inhibitor.
2. In Article 1, The above second reaction inhibitor is a gap filling method formed by removing at least a portion of the ligand having the adsorption characteristics of the above first reaction inhibitor using a specific gas.
3. In Article 2, The above second reaction inhibitor is a gap filling method having a higher adsorption density than the above first reaction inhibitor.
4. In Article 2, A gap filling method in which the specific gas mentioned above includes water ( H₂O ), ammonia ( NH₃ ), or hydrogen ( H₂ ).
5. In Article 1, The density gradient of the first reaction inhibitor above is a gap filling method determined by the following equation. Here, ℓ is the depth (nm) to the position where the first reaction inhibitor is adsorbed on the sidewall of the gap, w is the width (nm) of the gap, P is the partial pressure (Pa) of the first reaction inhibitor in the reaction chamber, t is the exposure time (s) of the first reaction inhibitor, S is the saturation dose (≈ 2.5× 10¹⁸ molecules · meter), m is the molecular mass (kg) of the first reaction inhibitor, k is the Boltzmann constant (Boltzman factor, 1.38× 10⁻²³ J/K), and T is the temperature (K) in the reaction chamber.
6. In Article 1, The above-mentioned first reaction inhibitor is a gap filling method comprising a central metal and an organic ligand.
7. In Article 6, A gap filling method comprising the above organic ligand a Cp(cyclopentadienyl) ligand or a Cp * (pentamethyl cyclopentadienyl) ligand.
8. In Article 6, The above-mentioned first reaction inhibitor is a gap filling method comprising (Me 2 N) 2 SiMe 2, TiCp*(OMe) 3 , Ti(CpMe)(O i Pr) 3, Ti(CpMe)(NMe 2 ) 3 , ZrCp(NMe 2 ) 3 ZrCp 2 Cl 2, Zr(Cp 2 CMe 2 )Me 2, Zr(Cp 2 CMe 2 )Me(OMe), HfCp(NMe 2 ) 3, Hf(CpMe)(NMe 2 ) 3 or Ru(EtCP) 2 ,
9. In Article 6, The above-mentioned first reaction inhibitor is a gap filling method having the same center metal as the above-mentioned first reactant.
10. In Article 1, The above second reaction inhibitor is a gap filling method that is oxidized by ozone ( O3 ) or oxygen ( O2 ) plasma.
11. In Article 1, The above second reaction inhibitor is a gap filling method that does not react with water ( H₂O ) or oxygen ( O₂ ).
12. In Article 1, The above-mentioned first reactant is a gap-filling method comprising TiCl₄ , Ti(O i Pr) ₄ , Ti( NMe₂ ) ₄ , Ti(NMeEt) ₄ , Ti( NEt₂ ) ₄ , ZrCl₄ , Zr(NMe₂)₄, Zr(O t Bu)₄ , ZrCp₂Me₂ , Zr ( MeCp) ₂ (OMe) Me , HfCl₄ , Hf(NMe₂) ₄ , Hf(NEtMe) ₄ , Hf( NEt₂ ) ₄ , HfCp₂Me₂ , Hf(MeCp) ₂ (OMe)Me, or β-diketonate Ru precursor, dicarbonyl-bis( 5 -methyl- 2,4 - hexanediketonato ) Ru(II) (“Carish”C₁₆H₂₂O₆Ru),
13. In Article 1, A gap filling method in which the second reactant comprises water ( H₂O ) or oxygen ( O₂ ).
14. In Article 1, A gap filling method further comprising the step of forming a first filled layer by repeatedly performing the formation of the first precursor film and the formation of the first atomic film in a plurality of cycles.
15. In Article 14, A gap filling method in which the density of the first reaction inhibitor decreases toward the bottom of the gap, thereby forming the first filling layer upward from the bottom of the gap.
16. In Article 14, After forming the first filling layer above, A step of forming a second reaction inhibitory film on the sidewall of the gap; A step of forming a second precursor film on the upper surface of the first charged layer and on the side wall of the gap adjacent to the upper surface of the first charged layer; and A gap filling method comprising the step of forming a second atomic film on the upper surface of the first filling layer and on the side wall of the gap adjacent to the upper surface of the first filling layer.
17. In Article 16, A gap filling method further comprising the step of forming a second filling layer upward from the upper surface of the first filling layer by repeatedly performing the formation of the second precursor film and the formation of the second atomic film in a plurality of cycles.
18. In Article 1, Before forming the first reaction inhibitor film on the sidewall of the gap, A gap filling method further comprising the step of forming an upper atomic film on the surface of the substrate adjacent to the entrance of the gap.
19. In Article 18, A gap filling method in which the upper atomic film comprises the same material as the first atomic film.
20. In Article 19, The above upper atomic film is a gap filling method formed by reacting the first reaction inhibitor with ozone ( O3 ) or oxygen ( O2 ) plasma.

Description

Method and apparatus for filling gap using atomic layer deposition The present disclosure relates to a gap filling method and apparatus using atomic layer deposition. Atomic layer deposition is used as a process to fill gaps, such as trenches formed in a substrate. Since atomic layer deposition utilizes surface reactions, filling a gap using atomic layer deposition allows for the formation of a uniform thickness on the surrounding surface of the gap, thereby minimizing the formation of voids. However, if the gap has a high aspect ratio, the size of the gap entrance may be smaller than the size of the gap interior, so voids may still be formed even when using atomic layer deposition. FIGS. 1 to 13 are drawings for explaining a gap filling method according to an exemplary embodiment. Figures 14a and 14b are experimental results showing the blocking characteristics of a reaction inhibitor film formed by performing a water ( H₂O ) process on TiCp * (OMe) ₃ . Figures 15a and 15b are experimental results showing the gap filling characteristics depending on whether a water process is performed when the interior of a high aspect ratio gap formed on a SiO2 substrate is filled with TiO2 . FIGS. 16 to 19 are drawings for illustrating a gap filling method according to other exemplary embodiments. FIGS. 20 to 22 are drawings for illustrating a gap filling method according to other exemplary embodiments. FIG. 23 is a schematic plan view illustrating an atomic layer deposition apparatus according to an exemplary embodiment. FIG. 24 is a cross-sectional view taken along the line I-I' of FIG. 23. FIG. 25 is a cross-sectional view taken along the line II-II' of FIG. 23. FIGS. 26a to 26c illustrate a meta-lens implemented according to an exemplary embodiment. FIG. 27 illustrates augmented reality glasses (AR Glasses) as an example of a near-eye display device. FIG. 28 illustrates an example of a DRAM including an interconnect structure implemented according to an exemplary embodiment. FIG. 29 illustrates an example of a three-dimensional NAND flash memory device implemented according to an exemplary embodiment. Hereinafter, exemplary embodiments will be described in detail with reference to the attached drawings. In the drawings below, the same reference numerals denote the same components, and the size of each component in the drawings may be exaggerated for clarity and convenience of explanation. Meanwhile, the embodiments described below are merely illustrative, and various modifications are possible from these embodiments. In the following, terms designated as "upper" or "upper" may include not only those located directly above, below, to the left, or to the right in contact, but also those located above, below, to the left, or to the right without contact. Singular expressions include plural expressions unless the context clearly indicates otherwise. Furthermore, when a part is described as "comprising" a certain component, this means that, unless specifically stated otherwise, it does not exclude other components but may include additional components. The use of the term “above” and similar descriptive terms may apply to both the singular and plural forms. Unless there is an explicit description of the order of the steps constituting the method or a description contrary to it, these steps are not necessarily limited to the order described and may be performed in a suitable order. All examples or the use of exemplary terms are merely for the purpose of describing the technical concept in detail, and unless limited by the claims, the scope is not limited by such examples or exemplary terms. Recently, high-efficiency planar meta-lenses with high precision and high aspect ratio nanostructures have been developed, and such meta-lenses can be widely applied in fields such as laser-based microscopy, imaging, and spectroscopy. The gap filling method described below can be applied as a manufacturing technology for meta-surface devices that require nanostructures with high precision and high aspect ratio. With the high integration of semiconductor devices, the planar size of discrete devices or wiring continues to decrease, while the thickness of the layers constituting the semiconductor device is becoming increasingly thicker. Furthermore, as multilayer technology for three-dimensionally arranging or connecting discrete devices constituting the semiconductor device develops, large step heights are often formed on the surface of the process substrate at each process stage, and deep gaps with high aspect ratios are frequently formed. When forming an interlayer insulating film on a process substrate with such large step heights and deep gaps with high aspect ratios, voids are prone to forming. The gap filling method described below can be applied as a technique for filling deep gaps with high aspect ratios formed on a process substrate in the manufacturing of semiconductor devices. In addition, the gap filling method described belo