Getter Material Oxidation for Microelectronic Encapsulation
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Solution Overview
Problem
Getter materials used in encapsulating microelectronic and nanoelectronic devices are highly reactive with ambient air, leading to unwanted chemical alterations and hydrogen degassing, which can be detrimental to device operation, and existing protection methods are costly and technologically challenging.
Innovation Solution
A process involving oxidation or nitriding of getter materials under a dry dioxygen or dinitrogen atmosphere forms a protective oxide or nitride layer, preventing chemical alteration and allowing for controlled degassing, thereby enhancing the getter's pumping capacity and enabling lower thermal activation temperatures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If getter material is exposed to ambient air after deposition, then it absorbs gaseous molecules (oxygen, nitrogen, water vapor), but this forms an oxide layer and introduces hydrogen that requires lengthy heat treatment for degassing
Solution Approach 1:
The patent applies preliminary action by forming a protective oxide layer on the getter material surface through controlled oxidation in a dry atmosphere before the getter is exposed to ambient air. This pre-formed protective layer prevents unwanted chemical alterations and hydrogen absorption during subsequent handling, eliminating the need for lengthy degassing heat treatment later. The oxidation step is performed in advance as part of the getter fabrication process, transforming a potential harmful exposure into a beneficial protective measure.
2Reliability
If a thin layer of noble metal is deposited to protect getter material from oxidation, then chemical alteration is prevented, but additional cost and control of layer thickness are required
Solution Approach 1:
The patent replaces expensive noble metal protective layers with a thin oxide layer formed by controlled oxidation of the getter material itself. This oxide layer is inexpensive to form, can be created in-situ during the getter deposition process, and does not require precise thickness control like noble metal layers. The oxidation process naturally forms a thin, uniform protective layer that is sufficient to prevent further oxidation and contamination, eliminating the need for additional deposition steps and thickness monitoring.
3Quantity of substance
If getter material is deposited as a thin layer, then it is effective for pressure control, but it has high reactivity with ambient air requiring immediate encapsulation
Solution Approach 1:
The patent applies preliminary action by performing controlled oxidation of the thin getter layer immediately after deposition while still in the vacuum chamber or during the encapsulation process. This creates a protective oxide skin on the thin getter layer before it encounters ambient air, allowing the getter to be handled and processed in ambient conditions without fear of unwanted chemical reactions. The thin layer maintains its pressure control efficiency while the pre-formed oxide layer provides ambient air stability.
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 protective layer effectively absorbs and desorbs gaseous molecules, preventing chemical alteration of the getter material, increasing its pumping capacity, and allowing for lower thermal activation temperatures without the need for pre-degassing, thus improving the encapsulation process and device reliability.
Implementation Method 1
the getter material then absorbs the gases of the ambient air (oxygen, nitrogen, monoxide and dioxide of carbon) as well as the vapor of water present in the ambient air
Implementation Method 2
a getter material is a material comprising, intrinsically and/or due to its microscopic or nanoscopic morphology, absorbent and/or adsorbent properties with respect to gaseous molecules
Implementation Method 3
Such exposure of the getter material to ambient air forms an oxide layer a few nanometers thick at the surface of the layer of getter material
Implementation Method 4
a process for treating a getter material is proposed, comprising at least one step of oxidation and/or nitriding of the getter material implemented under a dry atmosphere of dioxygen and/or dinitrogen, forming a protective layer based on oxide and/or nitride of the getter material
Implementation Method 5
a process for treating a getter material is proposed, comprising at least one step of oxidation and/or nitriding of the getter material implemented under a dry atmosphere of dioxygen and/or dinitrogen
Implementation Method 6
The molecules absorbed and/or adsorbed by the protective layer based on oxide and/or nitride can be desorbed by the subsequent implementation of simple degassing
Data Source
Figure 1~3
Figure 4
AI summary
The method involves oxidizing and/or nitriding a getter material (104) conducted under dry atmosphere of dioxygen and/or dinitrogen at a temperature between 50 and 120 degrees Celsius over a period of 1 to 10 minutes. A protective layer (106) composed of oxide and/or nitride of the getter material is formed, where the getter material is formed as a thin layer. An independent claim is also included for a method for encapsulation of a getter material in a cavity.