HDP CVD Moisture Barrier Films for Thin OLED Encapsulation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional capacitively coupled plasma (CCP) methods for depositing barrier films in OLED and LCD structures result in thick, UV-absorbing films with high refractive indices, which are not optimal for thin film encapsulation and transistor applications.
Innovation Solution
A high density plasma chemical vapor deposition method using frequencies of 2 MHz to 13.56 MHz or 2.45 GHz, with plasma densities between 10^11 and 10^12 cm^-3, to deposit silicon oxynitride, silicon nitride, or silicon oxide barrier films at temperatures below 250°C, achieving thicknesses less than 3000 Å, refractive indices between 1.45 and 1.95, and zero absorption at UV wavelengths.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional capacitively coupled plasma (CCP) arrangement is used to deposit barrier films, then the deposition process can be accomplished, but the resulting films are thick (7000-10000 Angstroms) with high refractive index (>1.7) and UV absorption
Solution Approach 1:
The patent changes the plasma generation parameters by using inductive coupling instead of capacitive coupling, operating at different frequency ranges (2 MHz to 13.56 MHz), and adjusting plasma density to achieve thinner films with improved optical properties. This parameter change resolves the contradiction by enabling precise thickness control while maintaining process feasibility
Solution Approach 2:
The patent substitutes the capacitive coupling mechanism with inductive coupling mechanism for plasma generation. This replacement fundamentally changes how plasma is generated and maintained, allowing for better control over film deposition characteristics and achieving the desired thin film properties without sacrificing manufacturing ease
2Object-affected harmful factors
If high plasma density (10^11 to 10^12 cm^-3) is used in HDP CVD, then thin barrier films with reduced UV absorption can be deposited, but the deposition requires specific frequency control (2 MHz to 13.56 MHz or 2.45 GHz)
Solution Approach 1:
The patent utilizes high plasma density (10^11 to 10^12 cm^-3) achieved through inductive or microwave coupling to deposit thin barrier films with minimal UV absorption. The specific frequency ranges (2 MHz to 13.56 MHz for inductive, 2.45 GHz for microwave) are optimized to generate the required plasma density while managing the complexity of frequency control systems
3Object-affected harmful factors
If barrier films are deposited at low temperature (<250°C), then plasma damage to substrates is minimized, but the deposition process requires precise temperature control
Solution Approach 1:
The patent deposits barrier films at low temperatures (<250°C) using HDP CVD with inductive or microwave plasma coupling. This temperature control minimizes plasma damage to substrates while the precise temperature management is achieved through controlled plasma parameters and substrate cooling mechanisms inherent in the HDP process
4Length of stationary object
If thin barrier films (<3000 Angstroms) are deposited, then the encapsulation structure becomes more compact, but the deposition time and process precision requirements increase
Solution Approach 1:
The patent achieves thin barrier film deposition (<3000 Angstroms) by utilizing high plasma density in HDP CVD process. The high plasma density enables faster deposition rates that reduce deposition time despite the reduced thickness requirement, while precise control of plasma parameters ensures consistent film quality
Solution Approach 2:
The HDP CVD process maintains continuous plasma generation and material deposition, ensuring steady film growth even at reduced thickness levels. This continuous process action allows for efficient deposition of thin films without significant increases in process time
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enables the deposition of thin, high-quality moisture barrier films with reduced thickness and optical absorption, minimizing stress and deposition time, while maintaining effective moisture barrier properties and low plasma damage.
Implementation Method 1
A moisture barrier film is deposited in a high density plasma chemical vapor deposition chamber at a temperature of less than about 250 degrees Celsius
Implementation Method 2
depositing a barrier layer over the substrate using the high density plasma arrangement
Implementation Method 3
a plasma density of about 10^11 cm^3 to about 10^12 cm^3
Implementation Method 4
an inductively coupled plasma power frequency of about 2 MHz to about 13.56 MHz or a microwave power frequency of about 2.45 GHz
Data Source
AI summary
Embodiments of the present disclosure generally relate to moisture barrier films utilized in an organic light emitting diode device. A moisture barrier film is deposited in a high density plasma chemical vapor deposition chamber at a temperature of less than about 250 degrees Celsius, an inductively coupled plasma power frequency of about 2 MHz to about 13.56 MHz or a microwave power frequency of about 2.45 GHz, and a plasma density of about 1011 cm3 to about 1012 cm3. The moisture barrier film comprises a material selected from the group consisting of silicon oxynitride, silicon nitride, and silicon oxide. The moisture barrier film has a thickness of less than about 3,000 Angstroms, a refractive index between about 1.45 and 1.95, and an absorption coefficient of about zero at UV wavelengths. The moisture barrier film may be utilized in a thin film encapsulation structure or a thin film transistor.