KR-102963481-B1 - Conformal damage-free encapsulation of chalcogenide materials

KR102963481B1KR 102963481 B1KR102963481 B1KR 102963481B1KR-102963481-B1

Abstract

Methods and apparatuses for forming an encapsulation bilayer on a chalcogenide material on a semiconductor substrate are provided. The methods involve forming a bilayer comprising a barrier layer deposited using PP-PECVD (pulsed plasma-enhanced chemical vapor deposition) directly on the chalcogenide material and an encapsulation layer deposited using PEALD (plasma-enhanced atomic layer deposition) on the barrier layer. In various embodiments, the barrier layer is formed using a halogen-free silicon precursor, and the encapsulation layer deposited by PEALD is formed using a halogen-containing silicon precursor and a hydrogen-free nitrogen-containing reactant.

Inventors

심즈, 제임스 사무엘
라이, 비크란트
맥케로우, 앤드류 존
센, 메이화
릴, 토르스텐 베르튼
탕, 셰인
켈츠너, 캐스린 머세드
호앙, 존
둘킨, 알렉산더
첸, 다나

Assignees

램 리써치 코포레이션

Dates

Publication Date: 20260511
Application Date: 20190821
Priority Date: 20180824

Claims (10)

A step of providing a substrate comprising one or more exposed layers of a chalcogenide material in a plasma chamber; A step of depositing a first silicon nitride layer in the plasma chamber by exposing one or more exposed layers of the chalcogenide material to a pulsed halogen-free plasma; and A method comprising the step of depositing a second silicon nitride layer on the first silicon nitride layer in a plasma chamber by atomic layer deposition using alternating pulses of a halogen-containing silicon-containing precursor and a nitrogen-containing reactant without destroying the vacuum.
In Article 1, A method in which the first silicon nitride layer is deposited using pulsed plasma plasma-enhanced chemical vapor deposition.
In Article 1, A method in which the first silicon nitride layer prevents damage to the one or more exposed layers of the chalcogenide material when the second silicon nitride layer is deposited on the one or more exposed layers of the chalcogenide material.
In Article 1, A method in which the pulsed halogen-free plasma is ignited in an atmosphere containing a silane precursor and ammonia.
A step of providing a substrate comprising one or more exposed layers of a chalcogenide material; A step of depositing a first silicon nitride layer by exposing one or more exposed layers of the chalcogenide material to a pulsed halogen-free plasma; and After depositing the first silicon nitride layer, the method comprises the step of depositing a second silicon nitride layer on the first silicon nitride layer by atomic layer deposition using alternating pulses of a halogen-containing silicon-containing precursor and a nitrogen-containing reactant, and A method in which the above halogen-free plasma is pulsed at a duty cycle of 5% to 20%.
In any one of paragraphs 1 to 4, A method comprising the step of further exposing the first silicon nitride layer to a post-treatment plasma to densify the first silicon nitride layer after depositing the first silicon nitride layer and before depositing the second silicon nitride layer.
In a method for processing substrates, A step of providing a substrate comprising one or more exposed layers of a chalcogenide material in a plasma chamber; A step of depositing a first silicon nitride layer having a first density directly on the one or more exposed layers of the chalcogenide material in the plasma chamber by exposing one or more exposed layers of the chalcogenide material to a pulsed plasma; and A step of depositing a second silicon nitride layer having a second density on a first silicon nitride layer having a first density by atomic layer deposition in the plasma chamber, wherein the step of depositing the first silicon nitride layer and the step of depositing the second silicon nitride layer occur without destroying the vacuum, by the step of depositing the second silicon nitride layer. The method comprises the step of forming an encapsulation bilayer on the chalcogenide material, the first silicon nitride layer having the first density and the second silicon nitride layer having the second density, and The first density is smaller than the second density, and A substrate processing method in which the first silicon nitride layer is positioned between one or more exposed layers of the chalcogenide material and the second silicon nitride layer.
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In a method for processing substrates, A step of providing a substrate comprising one or more exposed layers of a chalcogenide material; A step of depositing a first silicon nitride layer having a first density directly on one or more exposed layers of the chalcogenide material; and By the step of depositing a second silicon nitride layer having a second density on the first silicon nitride layer having a first density, The method comprises the step of forming an encapsulation bilayer on the chalcogenide material, the first silicon nitride layer having the first density and the second silicon nitride layer having the second density, and The first density is smaller than the second density, and The first silicon nitride layer is located between one or more exposed layers of the chalcogenide material and the second silicon nitride layer, and A substrate processing method comprising further a step of exposing the first silicon nitride layer to a post-processing plasma to densify the first silicon nitride layer to a density between the first density and the second density after depositing the first silicon nitride layer and before depositing the second silicon nitride layer.
In an apparatus for processing a semiconductor substrate, An etching chamber for etching a semiconductor substrate having one or more layers of chalcogenide materials to form a pattern of stacks of chalcogenide materials on the semiconductor substrate; A deposition chamber for depositing an encapsulated double layer on the semiconductor substrate; A wafer transfer tool for transferring the semiconductor substrate between the etching chamber and the deposition chamber without destroying the vacuum; and The following actions: A step of etching a semiconductor substrate having one or more layers of chalcogenide materials to form a pattern of the chalcogenide materials in the etching chamber; and A substrate processing apparatus comprising a controller having instructions for performing the step of depositing the encapsulated bilayer on the semiconductor substrate using one or both of a pulsed plasma plasma-enhanced chemical vapor deposition (PP-PECVD) process and a plasma-enhanced atomic layer deposition (PEALD) process within the deposition chamber.

Description

Conformal damage-free encapsulation of chalcogenide materials Citation as a reference A PCT application form has been filed concurrently with this specification as part of this application. Each application claiming priority or interest, as identified in the PCT application form filed concurrently with this application, is incorporated by reference in its entirety for all purposes. The manufacturing of semiconductor devices often involves the formation of memory stacks that are sensitive to oxidation and moisture and may not withstand high-temperature operations or exposure to energetic species. As a result, memory stacks are often encapsulated prior to subsequent processing. However, some methods for depositing encapsulation layers may damage process chamber components or substrate materials. Additionally, some techniques may fail to form sufficiently thin and sealed layers. The description of the background technology provided in this specification is intended to provide the general context of the present disclosure. The work of the inventors named in this specification to the extent described in this background technology section, as well as aspects of the technology that may not otherwise be recognized as prior art at the time of filing, are not explicitly or implicitly recognized as prior art to the present disclosure. Methods for processing semiconductor substrates are provided herein. One embodiment comprises a method comprising: providing a substrate comprising one or more exposed layers of a chalcogenide material; depositing a first silicon nitride layer by exposing one or more exposed layers of the chalcogenide material to a pulsed halogen-free plasma; and depositing a second silicon nitride layer on the first silicon nitride layer by atomic layer deposition using alternating pulses of a halogen-containing silicon-containing precursor and a nitrogen-containing reactant after depositing the first silicon nitride layer. In various embodiments, the first silicon nitride layer is deposited using pulsed plasma plasma-enhanced chemical vapor deposition. In some embodiments, the pulse of the nitrogen-containing reactant during the deposition of the second silicon nitride layer comprises one pulse of nitrogen gas without hydrogen gas and one pulse of hydrogen gas without nitrogen gas. In various embodiments, the nitrogen-containing reactant is pulsed during the generation of plasma. In some embodiments, the pulse of the nitrogen-containing reactant during the deposition of the second silicon nitride layer comprises one pulse of nitrogen plasma without hydrogen and one pulse of hydrogen plasma without nitrogen. In some embodiments, the first silicon nitride layer prevents damage to one or more exposed layers of the chalcogenide material when the second silicon nitride layer is deposited on one or more exposed layers of the chalcogenide material. The first silicon nitride layer may be deposited on the sidewalls of one or more exposed layers of the chalcogenide material with a thickness of about 5 Å to about 10 Å. In various embodiments, a pulsed halogen-free plasma is ignited in an atmosphere containing a silane precursor and ammonia. For example, the silane precursor may be introduced into a mixture containing nitrogen and an ammonia atmosphere. In some embodiments, the ratio of silane precursor to nitrogen in the mixture is at least about 30:1. Ammonia may be introduced into a mixture containing hydrogen and an ammonia atmosphere. The ratio of ammonia to hydrogen in the mixture may be at least about 30:1. In various embodiments, the halogen-free plasma is pulsed with a duty cycle of about 5% to about 20%. In some embodiments, the halogen-free plasma is pulsed between 0 W and plasma power per substrate of about 150 W to about 250 W. In some embodiments, one or more exposed layers of chalcogenide material are part of an ovonic threshold switching device. One or more exposed layers of chalcogenide material may be part of a phase change device. In various embodiments, the method also includes the step of exposing the first silicon nitride layer to a post-treatment plasma to densify the first silicon nitride layer after depositing the first silicon nitride layer and before depositing the second silicon nitride layer. In some embodiments, at least one of the first silicon nitride layer and the second silicon nitride layer is deposited at a substrate temperature of about 250°C or less. The nitrogen-containing reactant may be hydrogen-free. In some embodiments, the halogen-containing silicon-containing precursor contains iodine, bromine, or a combination thereof. In some embodiments, the method also includes the step of etching a substrate comprising one or more exposed layers of chalcogenide material before depositing a first silicon nitride layer, and the deposition and etching of the first silicon nitride layer are performed without destroying the vacuum. In some embodiments, the deposition of the first silico