Cavity Structure Formation via Selective Adhesion
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Solution Overview
Problem
Conventional semiconductor processing techniques find it difficult to create devices with cavities or enclosed spaces, such as capacitors and fuel cells, due to the filling of trenches with deposited materials, which hinders the formation of reduced-size or high-performance devices.
Innovation Solution
A method involving a substrate with recessed and protruding surface portions, where a liquid mixture with specific chemical affinities is used to form a second layer that adheres to the first layer, creating a cavity, and a dielectric fluid with a higher dielectric constant is introduced to enhance capacitance or confine gases in fuel cells.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional semiconductor processing techniques are used to fabricate device structures, then standard layered structures can be achieved, but cavities or enclosed spaces cannot be formed because deposited material fills the bottom and coats the sides of trenches instead
Solution Approach 1:
Instead of trying to deposit material into a trench to form a cavity (which fails because material fills the trench), the invention inverts the approach: a planar layer is deposited first, then a trench is etched through it, and finally material is deposited on the exposed surfaces. This reversal of the sequence enables cavity formation where conventional approaches fail.
Solution Approach 2:
The planar layer is formed in advance before the trench is created. This preliminary formation of the planar layer provides a surface that can subsequently be etched and have material deposited on its exposed surfaces, enabling the cavity structure to be built step-by-step rather than attempting to form it in a single deposition step.
2Productivity
If trenches are filled with deposited material to form device structures, then standard fabrication can proceed, but cavities or enclosed spaces are lost
Solution Approach 1:
The fabrication process is segmented into distinct steps: forming the planar layer, etching the trench, and then depositing material on the exposed surfaces. This segmentation allows each step to be optimized independently, ensuring both efficient fabrication and precise cavity formation, rather than attempting to achieve both goals in a single step.
3Volume of moving object
If devices are miniaturized to reduce size, then device density increases, but conventional techniques cannot form the required cavity structures
Solution Approach 1:
The invention transitions from attempting to form cavities in the vertical dimension (by depositing into trenches) to forming them by creating enclosed spaces through planar layers and sidewall deposition. This dimensional approach change enables cavity formation in miniaturized devices where vertical trench filling is no longer feasible.
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 allows for the fabrication of devices with increased capacitance and reduced size, enabling the creation of miniaturized capacitors and fuel cells that utilize fluid or gas dielectric materials, improving performance and size constraints.
Implementation Method 1
The first material has a chemical affinity toward the second material such that the edge portion of the second layer adheres to the edge portion of the first layer
Implementation Method 2
a fluid, having a higher dielectric constant than a dielectric constant of the insulative layer, is provided in the cavity
Data Source
AI summary
A method of making a device. The method comprises providing a first layer including a first material on a surface of a substrate, removing a portion of the first layer and a corresponding portion of the substrate to form an opening in the first layer and a recessed portion in the surface of the substrate, and supplying a liquid mixture to the opening and the recessed portion. The liquid mixture includes a first component having a first chemical affinity to the first material and a second component having a second chemical affinity to the first material, which is smaller than the first chemical affinity. The method also includes removing the second component and forming a second layer including the first component. The second layer covers the recessed portion and adheres to an edge portion of the first layer, such that the second layer and the recessed portion define a cavity.