Semiconductor Metal Layer Isolation After Oxygen Etch Ashing
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Solution Overview
Problem
In semiconductor device manufacturing, by-products on the metal conductive layer can cause short circuits between adjacent layers, which existing processes fail to effectively prevent, leading to reduced yield and device performance.
Innovation Solution
A method involving the formation of a semiconductor structure with an initial sacrifice layer and mask layer on a substrate, using an oxygen source gas for etching and ashing to create a metal conductive layer and sacrifice layer, followed by an alkaline corrosion process to remove by-products and expose the conductive layer, and forming an isolation structure between adjacent layers to prevent short circuits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If existing processes are used to form metal conductive layers, then the manufacturing process can be completed, but by-products remain on the metal conductive layer causing short circuits between adjacent layers
Solution Approach 1:
An initial sacrifice layer is formed on the metal conductive layer before the metal conductive layer is exposed. This preliminary action allows the sacrifice layer to protect the metal conductive layer during subsequent etching and ashing processes, and enables complete removal of by-products without exposing the metal conductive layer to harmful chemicals
Solution Approach 2:
The sacrifice layer acts as an intermediary between the metal conductive layer and the etching/ashing processes. It mediates the removal of by-products while protecting the metal conductive layer, allowing complete by-product removal without direct contact between the metal conductive layer and corrosive chemicals
2Reliability
If multiple process steps are used to remove by-products and sacrifice layer, then complete removal can be achieved, but the process flow becomes complex
Solution Approach 1:
The etching and ashing processes are merged into a single step using oxygen source gas. This combined process simultaneously removes organic residues and forms the sacrifice layer, eliminating the need for separate etching and ashing steps and simplifying the overall process flow
Solution Approach 2:
The oxygen source gas serves multiple functions: it acts as an etching gas to remove organic residues, serves as an ashing gas to carbonize contaminants, and simultaneously forms the sacrifice layer on the metal conductive layer. This multi-functionality reduces the number of process steps required
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 method simplifies the process flow by removing both sacrifice layer and by-products using a single alkaline solution, reducing short circuits and improving the yield and reliability of semiconductor devices.
Implementation Method 1
forming a metal conductive layer and a sacrifice layer atop the metal conductive layer by etching the initial sacrifice layer and the initial metal conductive layer using an oxygen source gas as an etching gas
Implementation Method 2
removing the patterned mask layer by performing an ashing process using the oxygen source gas as the etching gas
Implementation Method 3
removing the sacrifice layer as well as a by-product formed during the etching and the ashing process and exposing the metal conductive layer by performing a corrosion process using an alkaline corrosion solution
Data Source
AI summary
A semiconductor structure is formed by: providing a substrate, wherein an insulation layer, an initial metal conductive layer, an initial sacrifice layer, and a mask layer stacking in sequence are formed on the substrate, wherein the initial sacrifice layer includes a metal oxide layer; forming a metal conductive layer and a sacrifice layer atop the metal conductive layer by etching the initial sacrifice layer and the initial metal conductive layer using an oxygen source gas as an etching gas based on a patterned mask layer; removing the patterned mask layer by performing an ashing process using the oxygen source gas as the etching gas; removing the sacrifice layer as well as a by-product formed during the etching and the ashing process and exposing the metal conductive layer by performing a corrosion process using an alkaline corrosion solution; and forming an isolation structure between adjacent metal conductive layers.