CN-122013104-A - The adhesion is improved by the interface bonding layer

Abstract

The present invention relates to a method and structure for improving adhesion of a glass substrate fine metal mask (GS-FMM) and an organometallic mask (GS-OMM) in an Organic Light Emitting Diode (OLED) process. The innovative technique deposits one or more Interfacial Bonding Layers (IBLs) between a glass substrate and a metal layer. The Interfacial Bonding Layer (IBL) is selected from metal oxides, nitrides or oxynitrides and forms covalent or ionic bonds with glass and the overlying metal to ensure durable adhesion. In addition, IBL provides resistance to hydrolytic degradation, improving long term stability of the mask during multiple cleaning and thermal cycling. The IBL has a Coefficient of Thermal Expansion (CTE) of less than 15 ppm/°C, which reduces thermal stresses during OLED processing. The invention ensures the adhesion performance, process stability and durability of the high-precision OLED display.

Inventors

• LI SHIYUN

Assignees

• 深圳迈可视维科技有限公司

Dates

Publication Date

20260512

Application Date

20251111

Priority Date

20241111

Claims (8)

1. 1. A glass substrate fine metal mask (GS-FMM) or glass substrate open metal mask (GS-OMM), comprising: A glass substrate; One or more Interfacial Bonding Layers (IBL) deposited on the glass substrate, wherein each Interfacial Bonding Layer (IBL) is selected from one or more of a metal oxide, a metal nitride, or a metal oxynitride, the Interfacial Bonding Layers (IBL) being used to passivate Si-OH groups of the glass surface to prevent hydrolytic degradation and enhance adhesion to the overlying metal layer; And one or more metal layers deposited over the Interfacial Bonding Layer (IBL) for forming a mask structure.
2. 2. The mask of claim 1, wherein the Interfacial Bonding Layer (IBL) is selected from one or more of aluminum oxide (Al 2 O 3 ), silicon nitride (Si 3 N 4 ), silicon oxynitride (SiON), hafnium oxide (HfO 2 ), zirconium oxide (ZrO 2 ), titanium oxide (TiO 2 ), magnesium oxide (MgO), or aluminum nitride (AlN).
3. 3. The mask of claim 1, wherein the Interfacial Bonding Layer (IBL) is formed using Atomic Layer Deposition (ALD), chemical Vapor Deposition (CVD), plasma Enhanced Chemical Vapor Deposition (PECVD), or other vapor deposition methods.
4. 4. Mask according to claim 1, wherein the thickness of the Interfacial Bonding Layer (IBL) ranges from 1nm to 200 nm, preferably 100 nm.
5. 5. The mask of claim 1, wherein the Interfacial Bonding Layer (IBL) has a Coefficient of Thermal Expansion (CTE) less than 15 ppm/°c to reduce thermal stress between the glass substrate and the overlying metal layer.
6. 6. The mask of claim 1, wherein the one or more metal layers comprise a multi-layer structure comprising an Adhesion Promoting Layer (APL), a Base Metal Layer (BML), and an open pore metal layer (AML).
7. 7. The mask of claim 1, wherein the mask comprises a single layer metal layer (AML) deposited on an Interfacial Bonding Layer (IBL).
8. 8. The mask of claim 1, wherein the glass substrate is plasma cleaned followed by metal deposition by Physical Vapor Deposition (PVD).

Description

The adhesion is improved by the interface bonding layer Technical Field The present invention relates to the field of Organic Light Emitting Diode (OLED) display fabrication, and is directed to enhancing adhesion, stability and durability in masking techniques, solving the bonding challenges between the substrate and the metal layer, ensuring reliable performance in accurate organic material deposition required for high resolution displays. Background Conventional invar-based Fine Metal Masks (FMMs) are widely used for accurate RGB material deposition, but face limitations when applied to larger-sized AMOLED panels. Invar is selected for its low Coefficient of Thermal Expansion (CTE), however, it is brittle under mechanical stress, which can lead to mask misalignment and distortion, especially in larger display panels. In addition, the segmented mask design for larger substrates can cause alignment difficulties, reducing production efficiency. In microOLED fabrication, the need for ultra-fine pixel patterns (over 2000 ppi) challenges the capabilities of conventional FMMs, even with advanced materials such as silicon nitride (FSM). However, silicon nitride based masks are often unsuitable for mass production because they are prone to failure under mechanical stress. The technology of patent application number 113209991 was filed on 12/9/2024, and was based on the development of FMM and organometallic mask (OMM) technology in AMOLED and microOLED display fabrication. These prior art techniques aim to address the challenges of scalability, mechanical stability, and precision, and thus promote high resolution organic material deposition for a wide variety of display sizes. Despite these advances, several key issues remain unsolved, particularly in GS-FMM and GS-OMM structures that combine glass substrates with metal layers. Major challenges include insufficient interlayer adhesion, hydrolytic degradation, and long-term stability. These problems can affect the alignment of the mask during fabrication and reduce the operational lifetime over multiple uses. In GS-FMM and GS-OMM structures, poor adhesion between the glass substrate and the metal layer is a significant problem. Glass substrates typically have si—oh (silanol) groups on their surface, which tend to absorb moisture, leading to hydrolytic degradation and gradual weakening of adhesion. Such degradation accelerates under cleaning cycles and environmental exposure, leading to delamination and interface failure. Robust solutions require chemical and mechanical stability at the interface to resist environmental degradation and maintain adhesion over multiple uses. However, the existing methods have not fully satisfied the requirement of hydrolysis adhesion resistance at the glass-metal interface, showing room for improvement in the technology of improving adhesion in OLED mask fabrication. Disclosure of Invention The present invention introduces an Interface Bonding Layer (IBL) to improve adhesion between the glass substrate and the metal layer in the fine metal mask (GS-FMM) and the organometallic mask (GS-OMM) of the glass substrate in OLED fabrication. Unlike conventional methods that rely on direct adhesion or common metals (such as titanium, chromium, or nickel), the present invention emphasizes the use of metal oxides, nitrides, and oxynitrides as IBLs. These IBLs can form covalent or ionic bonds with the glass substrate and the overlying metal layer, thereby establishing a strong and stable interface that is resistant to hydrolytic degradation. IBL materials such as Al 2O3、Si3N4, siON, and HfO 2 are selected to be not only chemically stable, but also exhibit a Coefficient of Thermal Expansion (CTE) of less than 15 ppm/°c, thereby reducing potential thermal stresses. This helps to prevent problems such as delamination or cracking during deposition while maintaining strong adhesion. The core function of IBL is to act as a passivation coating covering Si-OH groups on the glass surface that are susceptible to degradation. Such degradation typically occurs due to exposure to air, moisture, and multiple cleaning cycles, which can weaken the interface over time. By removing these reactive groups, the IBL forms a stable and hydrolysis-resistant surface, thereby promoting reliable adhesion to the overlying metal layer. In critical steps such as backside HF etching, IBL, base Metal Layer (BML) and open-pore metal layer (AML) are protected by thick Photoresist (PR) or UV film to ensure they are not affected by the process. The application of IBL in the invention significantly improves the long-term stability and performance of GS-FMM and GS-OMM structures. The enhanced adhesion can prevent delamination during prolonged exposure to moisture or cleaning and maintain alignment accuracy in high resolution OLED fabrication. This ensures that the mask can withstand multiple deposition and cleaning cycles without degrading performance, making it suitable for microOLED