Dielectric Plug Formation via Selective Etching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional IC manufacturing processes, particularly for forming dielectric plugs, face challenges such as increased complexity and reduced throughput due to the need for chemical mechanical polishing (CMP) steps, which require removing the wafer from a vacuum process chamber for planarization, leading to inefficiencies and contamination risks.
Innovation Solution
A method is introduced that forms dielectric plugs by depositing a first dielectric layer over a workpiece, treating a portion of it to convert it into a second dielectric layer with enhanced etching selectivity, and selectively removing the second layer without using CMP, thereby eliminating the need for planarization steps and maintaining the workpiece within the process chamber, improving throughput.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If chemical mechanical polishing (CMP) is used to planarize the workpiece, then surface planarity is improved, but manufacturing throughput is reduced and contamination risk increases
Solution Approach 1:
The patent extracts and eliminates the CMP step from the manufacturing process by using selective etching to remove the second dielectric layer. This removes the need to take the workpiece out of the vacuum chamber for planarization, thereby maintaining continuous processing and improving throughput while still achieving the desired surface planarity through selective material removal.
Solution Approach 2:
The patent replaces the mechanical CMP process with a chemical etching process. Instead of using mechanical polishing to achieve surface planarity, the invention uses selective chemical etching to remove the second dielectric layer, substituting a chemical mechanism for a mechanical one to eliminate the need for chamber evacuation and re-entry.
2Manufacturing precision
If CMP steps are introduced for planarization, then surface quality is improved, but process complexity increases
Solution Approach 1:
The patent extracts the planarization function from the CMP process and achieves it through selective etching of the second dielectric layer. This eliminates the need for separate planarization equipment and process steps, reducing overall process complexity while maintaining surface quality through the selective removal of excess dielectric material.
Solution Approach 2:
The patent merges the planarization function into the existing selective etching process. By designing the dielectric layers with different etch selectivities, the same etching step that forms the dielectric plug also achieves surface planarity, combining multiple functions into a single process step and reducing overall process complexity.
3Manufacturing precision
If the workpiece is removed from the vacuum chamber for planarization, then surface planarity is achieved, but contamination risk increases
Solution Approach 1:
The patent maintains continuous processing by performing selective etching within the vacuum chamber without removing the workpiece. The useful action of etching continues uninterrupted, achieving surface planarity while the workpiece remains in the controlled vacuum environment, thereby eliminating contamination risks associated with chamber entry and exit.
Solution Approach 2:
The patent uses the vacuum chamber itself as an intermediary environment that allows selective etching to occur. By maintaining the workpiece within the vacuum chamber and using plasma or other in-situ etching methods, the chamber acts as a mediator that enables planarization without exposing the workpiece to external contamination sources.
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 enhances manufacturing efficiency by eliminating the need for CMP, reducing contamination risks, and maintaining the workpiece in the process chamber, thereby improving throughput and surface planarity without the use of CMP processes.
Implementation Method 1
a dielectric material is first deposited over the workpiece
Implementation Method 2
The treatment process may be an oxygenation process, a nitridation process, or a hydrogenation process.
Implementation Method 3
The treatment process may be an oxygenation process, a nitridation process, or a hydrogenation process.
Implementation Method 4
The treatment process may be an oxygenation process, a nitridation process, or a hydrogenation process.
Implementation Method 5
The second dielectric layer may then be selectively removed using a chemistry that is selective to the second dielectric layer.
Data Source
AI summary
A method according to some embodiments of the present disclosure includes providing a workpiece that include an opening and a top surface, depositing a dielectric material over the workpiece and into the opening to form a first dielectric layer that has a top portion over the top surface and a plug portion in the opening, treating the first dielectric layer to convert top portion into a second dielectric layer different from the first dielectric layer, and selectively removing the second dielectric layer.