Encapsulated Lanthanum Sputtering Target
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Solution Overview
Problem
Lanthanum materials used in sputtering targets react with air, leading to contamination and particulate formation in PVD chambers due to their hydrophilic nature, compromising deposited materials on substrates.
Innovation Solution
Encapsulated sputtering targets are developed with a lanthanum or lithium target layer coated with a titanium encapsulation layer, which is deposited using vapor deposition techniques to prevent exposure to water and oxygen, and can be removed during a plasma process prior to PVD to reveal the target layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If lanthanum materials are exposed to air during shipping and handling, then the target can be easily transported and installed, but contamination and particulate formation occur due to reaction with water and oxygen
Solution Approach 1:
A protective coating layer is applied as an intermediary between the lanthanum target material and the ambient air. This coating prevents direct contact and reaction between the hydrophilic lanthanum surface and water/oxygen in the air, thereby eliminating contamination while allowing easy shipping and handling of the target.
Solution Approach 2:
The protective coating is applied in advance before the target is exposed to air during shipping and handling. This preliminary protective action prevents the harmful reaction between lanthanum and air from occurring in the first place, allowing the target to be transported and installed without contamination risk.
2Object-affected harmful factors
If a protective coating is applied to prevent air exposure, then contamination is prevented, but the target requires an additional layer that must be removed before use
Solution Approach 1:
The protective coating is designed as a temporary protective layer that is discarded (removed) after it has served its purpose during shipping and handling. The coating is removed via plasma ashing or other removal techniques just before the PVD process, allowing the lanthanum target to be used without permanent additional complexity.
3Object-affected harmful factors
If the target is kept in vacuum or inert atmosphere, then contamination is prevented, but shipping and handling becomes more complex and costly
Solution Approach 1:
Instead of requiring complex vacuum or inert atmosphere systems for shipping and handling, a simple protective coating serves as an intermediary barrier. This coating allows the target to be transported and stored in normal atmospheric conditions while still preventing contamination, eliminating the need for complex atmosphere control systems.
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
The encapsulation effectively prevents contamination of the target layer, ensuring cleaner deposition processes and reducing particulate contamination in the PVD chamber, thereby improving the quality of deposited materials.
Implementation Method 1
an encapsulation layer containing titanium disposed on or over the target layer
Implementation Method 2
exposing the encapsulation layer to a plasma while removing the encapsulation layer and revealing an upper surface of the target layer
Implementation Method 3
exposing the encapsulation layer to a plasma while removing the encapsulation layer
Implementation Method 4
The encapsulation layer may be deposited over or onto the target material by a vapor deposition technique
Data Source
AI summary
Embodiments of the invention provide encapsulated sputtering targets and methods for preparing such targets prior to a physical vapor deposition (PVD) process. In one embodiment, an encapsulated target for PVD is provided which includes a target layer containing lanthanum disposed on a backing plate and an encapsulation layer containing titanium disposed on or over the target layer. In one example, the target layer contains metallic lanthanum or lanthanum oxide and the encapsulation layer contains titanium. The encapsulation layer may have a thickness within a range from about 1,000 Å to about 2,000 Å. In another embodiment, a method for preparing an encapsulated target prior to a PVD process is provided which includes positioning an encapsulated target within a PVD chamber and exposing the encapsulation layer to a plasma while removing the encapsulation layer and revealing an upper surface of the target layer.