US-12628590-B2 - Substrate processing method

Abstract

A substrate processing method using a substrate processing apparatus including a process chamber having a reaction space for processing a substrate including an underlayer and a multilayer pattern provided on the underlayer and formed by alternately stacking at least a plurality of first insulating layers and a plurality of second insulating layers on one another, a substrate supporter, a gas ejector, and a plasma reactor, includes a pretreatment step for forming a passivation layer by supplying, onto the substrate through the gas ejector, a pretreatment gas, and an etching step for selectively and at least partially etching the plurality of second insulating layers in a lateral direction relative to the plurality of first insulating layers by supplying, onto the substrate through the gas ejector, an etchant.

Inventors

• Min Su Kim

Assignees

• WONIK IPS CO., LTD.

Dates

Publication Date

20260512

Application Date

20230815

Priority Date

20221116

Claims (11)

1. 1 . A substrate processing method using a substrate processing apparatus comprising a process chamber having a reaction space for processing a substrate comprising an underlayer and a multilayer pattern provided on the underlayer and formed by alternately stacking at least a plurality of first insulating layers and a plurality of second insulating layers on one another, a substrate supporter coupled to the process chamber to support the substrate, a gas ejector coupled onto the process chamber to face the substrate supporter, and a plasma reactor disposed outside the process chamber and connected to the gas ejector, the substrate processing method comprising: a pretreatment step for forming a passivation layer by supplying, onto the substrate through the gas ejector, a pretreatment gas comprising a hydrogen-containing gas and an oxygen-containing gas; and an etching step for selectively and at least partially etching the plurality of second insulating layers in a lateral direction relative to the plurality of first insulating layers by supplying, onto the substrate through the gas ejector, an etchant comprising a halogen-containing gas, a hydrogen-containing gas, an oxygen-containing gas, and a halogen- and hydrogen-containing product produced by reaction of the halogen-containing gas and the hydrogen-containing gas, wherein, in the etching step, at least one of the halogen-containing gas and the hydrogen-containing gas is activated in the plasma reactor and supplied to the gas ejector in a form of radicals.
2. 2 . The substrate processing method of claim 1 , wherein, in the etching step, the halogen-containing gas and an inert gas are supplied to the plasma reactor, and the hydrogen-containing gas and the oxygen-containing gas are supplied to the gas ejector.
3. 3 . The substrate processing method of claim 1 , wherein, in the etching step, the halogen-containing gas and an inert gas are supplied to the plasma reactor, and the hydrogen-containing gas and the oxygen-containing gas are also supplied to the plasma reactor.
4. 4 . The substrate processing method of claim 1 , wherein, in the etching step, the hydrogen-containing gas and the oxygen-containing gas are supplied to the plasma reactor, and the halogen-containing gas is supplied to the gas ejector.
5. 5 . The substrate processing method of claim 1 , further comprising a removal step for removing the passivation layer, after the etching step.
6. 6 . The substrate processing method of claim 1 , wherein the passivation layer is formed on at least exposed portions of the underlayer, and wherein, in the etching step, the plurality of second insulating layers are selectively etched relative to the plurality of first insulating layers and the underlayer.
7. 7 . The substrate processing method of claim 6 , wherein the plurality of first insulating layers comprise silicon oxide (SiO 2 ) layers, wherein the plurality of second insulating layers comprise silicon nitride (SiN) layers, and wherein the underlayer comprises a polysilicon layer.
8. 8 . The substrate processing method of claim 1 , wherein, in the etching step, the halogen-containing gas is activated in the plasma reactor and supplied to the gas ejector in a form of radicals, and the hydrogen-containing gas and the oxygen-containing gas are supplied to the gas ejector in an inactive state.
9. 9 . The substrate processing method of claim 8 , wherein the hydrogen-containing gas and the oxygen-containing gas are supplied to the gas ejector through a connection pipe connecting the plasma reactor and the gas ejector.
10. 10 . The substrate processing method of claim 1 , wherein the halogen-containing gas comprises NF 3 gas, wherein the hydrogen-containing gas comprises NH 3 gas, and wherein the product comprises ammonium fluoride (NH 3 (HF) x ).
11. 11 . The substrate processing method of claim 1 , wherein the oxygen-containing gas comprises O 2 gas, O 3 gas, or N 2 O gas.

Description

CROSS-REFERENCE TO RELATED PATENT APPLICATION This application claims the priority under 35 U.S.C. § 119(a) to Korean Patent Application No. 10-2022-0154021, filed on Nov. 16, 2022, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to semiconductor manufacturing and, more particularly, to a substrate processing apparatus and a substrate processing method. 2. Description of the Related Art Various processes are performed in a vacuum atmosphere of a substrate processing apparatus to manufacture semiconductor devices. For example, a substrate may be loaded into a process chamber and a process of depositing a thin film on the substrate or etching a thin film deposited on the substrate may be performed. Herein, the substrate may be supported by a substrate supporter mounted in the process chamber, and a process gas may be ejected onto the substrate through a gas ejector mounted above the substrate supporter. Meanwhile, when one or more layer patterns are provided on the substrate, a plurality of layers may be exposed on the substrate. For example, insulating layers such as oxide layers and nitride layers may be exposed on the substrate. Thereafter, a process of selectively etching one of the insulating layers may be performed. Currently, because the insulating layers are required to have small thicknesses for highly integrated semiconductor devices, undesired insulating layers may be etched due to the lack of selectivity in the step of etching the insulating layers. In addition, an etchant may not easily penetrate into the thin insulating layers and thus normal wet etching may not be used. Dry etching using a halide-based etching gas is being studied but does not have a high etch selectivity. Furthermore, when a semiconductor layer is present under the insulating layers, there is a problem that the semiconductor layer is also etched when the insulating layers are etched. SUMMARY OF THE INVENTION The present invention provides a substrate processing method using dry etching with a high etch selectivity to manufacture highly integrated semiconductor devices. However, the above description is an example, and the scope of the present invention is not limited thereto. According to an aspect of the present invention, there is provided a substrate processing method using a substrate processing apparatus including a process chamber having a reaction space for processing a substrate including an underlayer and a multilayer pattern provided on the underlayer and formed by alternately stacking at least a plurality of first insulating layers and a plurality of second insulating layers on one another, a substrate supporter coupled to the process chamber to support the substrate, a gas ejector coupled onto the process chamber to face the substrate supporter, and a plasma reactor disposed outside the process chamber and connected to the gas ejector, the substrate processing method including a pretreatment step for forming a passivation layer by supplying, onto the substrate through the gas ejector, a pretreatment gas including a hydrogen-containing gas and an oxygen-containing gas, and an etching step for selectively and at least partially etching the plurality of second insulating layers in a lateral direction relative to the plurality of first insulating layers by supplying, onto the substrate through the gas ejector, an etchant including a halogen-containing gas, a hydrogen-containing gas, an oxygen-containing gas, and a halogen- and hydrogen-containing product produced by reaction of the halogen-containing gas and the hydrogen-containing gas, wherein, in the etching step, at least one of the halogen-containing gas and the hydrogen-containing gas is activated in the plasma reactor and supplied to the gas ejector in a form of radicals. In the etching step, the halogen-containing gas and an inert gas may be supplied to the plasma reactor, and the hydrogen-containing gas and the oxygen-containing gas may be supplied to the gas ejector. In the etching step, the halogen-containing gas and an inert gas may be supplied to the plasma reactor, and the hydrogen-containing gas and the oxygen-containing gas may also be supplied to the plasma reactor. In the etching step, the hydrogen-containing gas and the oxygen-containing gas may be supplied to the plasma reactor, and the halogen-containing gas may be supplied to the gas ejector. The substrate processing method may further include a removal step for removing the passivation layer, after the etching step. The passivation layer may be formed on at least exposed portions of the underlayer and, in the etching step, the plurality of second insulating layers may be selectively etched relative to the plurality of first insulating layers and the underlayer. The plurality of first insulating layers may include silicon oxide (SiO2) layers, t