JP-2026074622-A - Semiconductor wafer bonding apparatus and bonding method

Abstract

[Problem] To improve the bonding strength between wafers in the semiconductor manufacturing process with a simple configuration. [Solution] A semiconductor wafer bonding apparatus 34 for bonding semiconductor wafers W1 and W2 together, wherein the semiconductor wafers W1 and W2 are plasma-treated to activate their surfaces, then a high vacuum state is created within a predetermined time to polarize ions on the surfaces of the semiconductor wafers W1 and W2, and the application of a high-frequency power supply to at least one of the opposing semiconductor wafers W1 and W2 causes the ions to move on the surfaces of the semiconductor wafers W1 and W2, thereby increasing the bonding strength between the semiconductor wafers W1 and W2. [Selection Diagram] Figure 2

Inventors

• 長田厚
• 王笑寒

Assignees

• ＳＨＷ Ｔｅｃｈ株式会社

Dates

Publication Date

20260507

Application Date

20241021

Claims (10)

1. A semiconductor wafer bonding apparatus for bonding semiconductor wafers together, A semiconductor wafer bonding apparatus comprising: activating the surface of a semiconductor wafer by plasma treatment; polarizing ions on the surface of the semiconductor wafer by creating a high vacuum within a predetermined time; and increasing the bonding strength between the semiconductor wafers by causing the ions to move on the surface of the semiconductor wafers by applying a high-frequency power supply to at least one of the opposing semiconductor wafers.
2. A semiconductor wafer bonding apparatus that bonds semiconductor wafers held by parallel planar plasma electrodes by plasma processing, A semiconductor wafer bonding apparatus comprising: activating the surface of a semiconductor wafer by plasma treatment; polarizing ions on the surface of the semiconductor wafer by creating a high vacuum; and bonding the semiconductor wafers together by causing the ions to move across the surface of the semiconductor wafer when a high-frequency power supply is applied to the semiconductor wafer.
3. The semiconductor wafer bonding apparatus according to claim 1, wherein the predetermined time is 0 to 30 seconds.
4. The semiconductor wafer bonding apparatus according to claim 1, wherein the predetermined time is 0 to 5 seconds.
5. The semiconductor wafer bonding apparatus according to claim 2, wherein an electrostatic chuck is used as the parallel plate plasma electrode.
6. A method for joining semiconductor wafers, which joins semiconductor wafers together, A method for bonding semiconductor wafers, comprising: activating the surface of a semiconductor wafer by plasma treatment; polarizing ions on the surface of the semiconductor wafer by creating a high vacuum within a predetermined time; and increasing the bonding strength between the semiconductor wafers by applying a high-frequency power supply to at least one of the opposing semiconductor wafers, causing the ions to move across the surface of the semiconductor wafers.
7. A semiconductor wafer joining method comprising joining semiconductor wafers held by parallel planar plasma electrodes by plasma treatment, A method for joining semiconductor wafers, comprising: activating the surface of the semiconductor wafer by plasma treatment; polarizing ions on the surface of the semiconductor wafer by creating a high vacuum; and joining the semiconductor wafers together by applying a high-frequency power supply to the semiconductor wafer, causing the ions to move across the surface of the semiconductor wafer.
8. The semiconductor wafer bonding method according to claim 6, wherein the predetermined time is 0 to 30 seconds.
9. The semiconductor wafer bonding method according to claim 6, wherein the predetermined time is 0 to 5 seconds.
10. The method for joining semiconductor wafers according to claim 7, wherein an electrostatic chuck is used as the parallel plate plasma electrode.

Description

This invention relates to a semiconductor wafer bonding apparatus and bonding method for bonding semiconductor wafers together in a semiconductor manufacturing process, for example, by high-frequency ion flow bonding (RFIFB). Hybrid bonding, a part of conventional semiconductor manufacturing processes, includes, for example, a plasma treatment process, a cleaning process, a drying process, and a bonding process. In the plasma treatment process, for example, atmospheric pressure plasma or vacuum plasma is applied to the semiconductor wafer to activate its surface. In the cleaning process, for example, the semiconductor wafer is rotated around its central axis while a cleaning solution (pure water or chemical solution) is dropped onto its surface to clean it. In the drying process, for example, the semiconductor wafer is rotated at high speed around its central axis while water droplets are scattered from its surface. In the bonding process, for example, two semiconductor wafers, one above the other, that have undergone the plasma treatment and the other drying processes, are placed facing each other and bonded using a bonding device. In conventional bonding equipment, semiconductor wafers were placed on planar stages arranged opposite each other, and the pair of opposing semiconductor wafers were bonded together using a surface-activated bonding (SAB) method (hereinafter referred to as the "SAB method"), a room-temperature bonding process. Surface activation bonding involves ionizing an inert gas such as argon to create an ion beam, and then irradiating the surface of the materials to be bonded with this ion beam or plasma. This removes oxide films and contaminant layers present on the surface of the materials, activating the surface and enabling bonding at low temperatures and room temperatures. In the SAB method, when uniformly activating the entire surface of the semiconductor wafer at once and removing the oxide film, the surface of the semiconductor wafer was processed by sliding the semiconductor wafer or the ion beam source because the irradiation area of the ion beam was small. However, the SAB method suffered from poor surface uniformity of the semi-paper conductive wafer, resulting in surface roughness in some parts of the semiconductor wafer and a decrease in bonding strength between semiconductor wafers. Furthermore, the spot irradiation of the Ar ion beam caused movement of the semiconductor wafer or beam, leading to the generation of particles and voids. Japanese Patent Publication No. 2018-201022 This is a diagram of the semiconductor wafer bonding apparatus for one embodiment of the present invention.This is a diagram illustrating the plasma treatment and bonding process applied to a semiconductor wafer by a semiconductor wafer bonding apparatus according to one embodiment of the present invention.This is a process diagram showing plasma treatment and bonding processes on a semiconductor wafer using a semiconductor wafer bonding apparatus according to one embodiment of the present invention.This is a flowchart illustrating an example of high-frequency ionic fluid bonding.This is a plan view of a semiconductor manufacturing system in which a semiconductor wafer bonding apparatus according to one embodiment of the present invention is assembled.This is a side view of a semiconductor manufacturing system in which a semiconductor wafer bonding apparatus according to one embodiment of the present invention is assembled.This is a diagram showing the structure of a unipolar electrostatic chuck.This is a diagram showing the structure of a bipolar electrostatic chuck.This is a diagram showing the state when semiconductor wafers are joined together using a bipolar electrostatic chuck provided on a stage that constitutes a semiconductor wafer bonding apparatus according to one embodiment of the present invention. First, we will describe a semiconductor wafer bonding apparatus and bonding method according to one embodiment of the present invention. One embodiment of the semiconductor wafer bonding apparatus and bonding method involves bonding semiconductor wafers together using a plasma chamber or a vacuum chamber. In other words, the plasma chamber or vacuum chamber may also be referred to as a bonding chamber, bonding apparatus, bonding device, etc. [Technical Concept of the Invention] The technical concept of the present invention is a semiconductor wafer bonding apparatus that enhances the bonding strength between a pair of opposing wafers by bonding them together in a vacuum environment (plasma environment) inside a vacuum chamber where plasma processing is performed on the wafer, using RF high-frequency ion flow and Coulomb force (also called "electrostatic force"; the same applies hereinafter). The vacuum chamber may have a pair of holding parts positioned opposite each other on the stage, and by applying plasma between the wafers while the wafers are held in place by the holding parts, at least o