Metal Layer Fabrication via Dual Re-sputtering for Dielectric Protection
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Solution Overview
Problem
Conventional pre-cleaning processes for removing metal oxides during metal line formation in integrated circuits damage the dielectric layer, affecting its dielectric constant.
Innovation Solution
A method involving a first re-sputtering process with inert and metal ions to remove metal compounds from the dielectric layer, followed by a barrier formation and a second re-sputtering to remove the barrier, allowing for the deposition of a metal layer without damaging the dielectric layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a pre-cleaning process is used to remove metal oxide, then the metal oxide is removed, but the dielectric constant of the dielectric layer is damaged
Solution Approach 1:
The patent changes the parameters of the cleaning process by using re-sputtering with specific ion energies and compositions (inert gas ions mixed with metal ions) instead of conventional chemical cleaning methods. This physical cleaning approach removes metal oxide without the chemical damage that affects dielectric properties, thus resolving the contradiction between effective oxide removal and dielectric layer integrity
Solution Approach 2:
The patent replaces the chemical cleaning mechanism with a physical sputtering mechanism. By using ion bombardment to physically eject metal oxide atoms from the surface, the process avoids chemical reactions that would damage the dielectric layer, thereby maintaining dielectric constant while achieving effective oxide removal
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 effectively removes metal oxides without damaging the dielectric layer, maintaining its integrity and enabling successful metal layer formation in integrated circuits.
Implementation Method 1
a first re-sputtering is performed on the metal compound and the dielectric layer with inert ions and metal ions, wherein the metal compound is removed entirely during the first re-sputtering
Implementation Method 2
a second re-sputtering is performed on the barrier with the inert ions and the metal ions, wherein the barrier at a bottom of the trench is entirely removed during the second re-sputtering
Data Source
AI summary
A method of fabricating a metal layer includes performing a first re-sputtering to remove a metal compound formed on a conductive layer. The first re-sputtering includes bombarding the metal compound and a dielectric layer on the conductive layer by inert ions and metal atoms. Then, a barrier is formed on the dielectric layer and the conductive layer. Later, a bottom of the barrier is removed. Subsequently, a metal layer is formed to cover the barrier.