JP-2026514200-A - Organic small molecule inhibitors and methods for using them in thin film deposition.

JP2026514200AJP 2026514200 AJP2026514200 AJP 2026514200AJP-2026514200-A

Abstract

This invention discloses organic small molecule inhibitors and methods for using them in thin film deposition, and belongs to the field of semiconductor processing technology. The inhibitors include urea-based compounds, amino acid-based compounds, and amidine-based compounds. The method of use involves placing a HAR substrate in an atomic layer deposition apparatus, introducing the organic small molecule inhibitor into the reaction chamber in pulse form from a stainless steel source bottle, introducing a precursor into the reaction chamber in pulse form from a stainless steel source bottle, using an inert gas as a carrier gas, introducing the precursor into the reaction chamber in pulse form from an oxygen source into the reaction chamber in pulse form to generate an oxide thin film, introducing an inert gas into the reaction chamber, purging excess oxygen source and reaction byproducts, and repeating the above steps until a predetermined thickness is reached. Compared to previously reported inhibitor molecules, the inhibitors of this invention have two or more N and O atoms in their molecular structure, form multiple hydrogen bonds, have a better inhibitory effect, and significantly improve step coverage. [Selection Diagram] None

Inventors

程蘭云
張学奇
扈静
李建恒
朱思坤

Assignees

合肥安徳科銘半導体科技有限公司

Dates

Publication Date: 20260507
Application Date: 20240515
Priority Date: 20240408

Claims (10)

An organic small molecule inhibitor characterized by containing urea-based compounds, amino acid-based compounds, and amidine-based compounds.
The urea compound has a structure represented by formula I, (Equation I) The organic small molecule inhibitor according to claim 1, characterized in that, in formula I, R1, R2, R3, and R4 are each independently selected from the group consisting of hydrogen, halogen, and any group substituted with a heteroatom, the any group substituted with a heteroatom includes any substituted aliphatic, any substituted cyclic aliphatic or heterocyclic aliphatic, and any substituted aromatic, and the heteroatom is one or more of O, N, S, P, B, and Si.
The organic small molecule inhibitor according to claim 1, characterized in that the urea compound is one of urea, hydroxyethylurea, and semicarbazide.
The amino acid compound has the structure represented by formula II, (Formula II) The organic small molecule inhibitor according to claim 1, characterized in that, in formula II, R1 and R2 are each independently selected from the group consisting of hydrogen, halogen, and any group substituted with a heteroatom, the any group substituted with a heteroatom includes any substituted aliphatic, any substituted cyclic aliphatic or heterocyclic aliphatic, and any substituted aromatic, and the heteroatom is one or more of O, N, S, P, B, and Si.
The organic small molecule inhibitor according to claim 1, characterized in that the amino acid compound is one of glycine, alanine, and isoleucine.
Amidine compounds have a structure represented by formula III, (Formula III) The organic small molecule inhibitor according to claim 1, characterized in that, in formula III, R1, R2, R3, and R4 are each independently selected from the group consisting of hydrogen, halogen, and any group substituted with a heteroatom, the any group substituted with a heteroatom includes any substituted aliphatic, any substituted cyclic aliphatic or heterocyclic aliphatic, and any substituted aromatic, and the heteroatom is one or more of O, N, S, P, B, and Si.
The organic small molecule inhibitor according to claim 1, characterized in that the amidine compound is one of N,N'-diisopropyl-formamidine, N,N'-diisopropyl-acetamidine, N,N'-diisopropyl-propionamidine, N-hydroxyacetamidine, formamidine, acetamidine, and propionamidine.
Use of an organic small molecule inhibitor according to any one of claims 1 to 7 in thin film deposition on a high aspect ratio substrate, such as a HAR substrate.
Step S1 involves placing the HAR substrate into an atomic layer deposition apparatus, setting the reaction chamber temperature to 100-450°C, and evacuating it to 0-30 Pa. Step S2 involves placing an organic small molecule inhibitor in a stainless steel source bottle and connecting it to a reaction chamber, with the source bottle heated to 30-100°C and the pipeline heated to 50-150°C, using an inert gas as a carrier gas, and introducing the organic small molecule inhibitor into the reaction chamber in a pulsed manner. Step S3 involves introducing an inert gas into the reaction chamber and setting the purging time to 5-50 s, Step S4 involves placing the precursor in a stainless steel source bottle, connecting the source bottle to the reaction chamber via a conduit, heating the source bottle to 30-100°C, heating the conduit to 50-150°C, using an inert gas as the carrier gas, and introducing the precursor into the reaction chamber in a pulsed manner. Step S5 involves introducing an inert gas into the reaction chamber and setting the purging time to 5-50 s, Step S6 involves introducing an oxygen source into the reaction chamber in pulse form, with a pulse duration of 0.02-50 s and a flow rate of 20-200 sccm. Step S7 involves introducing an inert gas into the reaction chamber and setting the purging time to 5-50 s, The method for using an organic small molecule inhibitor in thin film deposition according to claim 8, characterized in that the steps S2-S7 are repeated for X cycles until a predetermined thickness is reached, the method comprising step S8 where X is an integer of 1 or more.
The method for using an organic small molecule inhibitor in thin film deposition according to claim 9, characterized in that the precursor is a Si-based precursor or a metal-based precursor.

Description

This invention belongs to the field of semiconductor processing technology, and more specifically, relates to organic small molecule inhibitors and methods of using them in thin film deposition. To continuously improve device size minimization and performance optimization, the semiconductor industry is facing increasingly high demands for device memory density. Atomic Layer Deposition (ALD) is an excellent coating method, and its significant advantages of isotropic growth and precise film thickness control have made it a crucial front-end process in semiconductor device manufacturing. In high aspect ratio (HAR) 3D nanostructures, such as pores or grooves, ALD deposition often forms seams or voids during the top-to-bottom gap-filling process, leading to a decrease in device performance, electrical or thermal conductivity, and mechanical performance. To address this problem, many researchers introduce inhibitors during the ALD deposition process to selectively inhibit deposition at the top of the HAR substrate and reduce or eliminate deposition at the bottom, thereby enhancing the uniformity of top-to-bottom filling, improving step coverage, and eliminating seams or voids. Patents CN104928654B and CN112400225A inactivate the surface and strengthen the nucleation barrier for ALD film deposition by introducing plasma inhibitors (such as N2 , Ar, He, H2 , NH3 , fluorides, amines, and alcohols). When the plasma inhibitor interacts with the substrate, the geometric shielding effect causes the bottom to receive far less plasma treatment than the top, improving the step coverage of thin film growth. However, the plasma can damage the substrate and is not suitable for use on HAR substrates with higher aspect ratios. Patents CN113818009A and US20230227972A1 use an ALD precursor as an inhibitor, and the inhibitor in the inhibitory layer exhibits a density gradient that decreases from top to bottom on a HAR substrate. For example, a TiO2 thin film is deposited by an ALD process of tetrakis(dimethylamino)titanium (TDMAT) and H2O , and the step coverage is improved by introducing the inhibitor Cp*Ti(OMe) 3 , where Cp* is pentamethylcyclopentadienyl. This is because the inhibitor Cp*Ti(OMe) 3 is strongly adsorbed to the substrate by eliminating -OMe, and because of the steric hindrance of the Cp* ligand and its weak reactivity with H2O , the Cp*Ti(OMe)x (1≦X≦2) on the substrate surface is less likely to be oxidized by H2O , making it difficult to form new Ti-O bonds and thus inhibiting the growth of the TiO2 thin film. Furthermore, Chi Thang Nguyen [1] et al. investigated the inhibitory mechanism of the inhibitor Cp*Ti(OMe) 3 in detail. Patent US20220119939A1 proposes organic small molecule inhibitors, such as triethylamine (TEA), tetrahydrofuran (THF), and ethylene glycol dimethyl ether (DME). These inhibitor molecules mildly physically adsorb onto the HAR substrate, competing with precursor molecules for the active site on the substrate surface. This inhibits excessive adsorption of the precursor to the substrate top surface, improving step coverage, although the effect needs to be improved. Based on previous research, organic small molecule inhibitors are less expensive, more readily available, more environmentally friendly, and easier to control the parameters of the deposition process compared to plasma gas inhibitors and ALD precursor-based inhibitors. Therefore, searching for organic small molecule inhibitors with better efficacy is a worthwhile research endeavor. The present invention aims to provide an organic small molecule inhibitor and a method for using it in thin film deposition, which solves the problem of the low effectiveness of conventional small molecule inhibitors for ALD deposition. The object of this invention can be achieved by the following technical solution. This invention provides organic small molecule inhibitors comprising urea-based compounds, amino acid-based compounds, and amidine-based compounds. Urea compounds have a structure represented by formula I. (Equation I) In Formula I, R1, R2, R3, and R4 are each independently selected from the group consisting of hydrogen, halogens, and any heteroatom-substituted groups. The heteroatom-substituted groups include any substituted aliphatic, any substituted cyclic aliphatic, or heterocyclic aliphatic, and any substituted aromatic group, and are typically C1-C10 alkyl, heteroalkyl, alkenyl, heteroalkenyl, alkynyl, heteroalkynyl, alkyl halide, alkenyl halide, alkynyl halide, or heterocyclic halide groups. Preferably, the urea compound is one of urea, hydroxyethylurea, and semicarbazide. Amino acid compounds have the structure represented by formula II. (Formula II) In Formula II, R1 and R2 are each independently selected from the group consisting of hydrogen, halogens, and any heteroatom-substituted groups. The heteroatom-substituted groups include any substituted aliphatic, any substituted cyclic aliphatic, or heterocyclic aliphatic, and any subst