Germanium Silicon Stacks 3D NAND Etch Selectivity
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Solution Overview
Problem
Conventional semiconductor processing technologies face challenges in achieving uniformity and control during the etch removal process of stacked memory structures, particularly in 3D NAND processing, due to material differences between placeholder layers and dielectric materials, leading to inconsistent patterning and defects.
Innovation Solution
The use of a germanium oxide placeholder layer instead of silicon nitride, allowing for a dry etch process that is more selective than conventional wet processing, and maintaining temperature sensitivity to ensure discrete layers during subsequent processing, forming alternating layers of silicon oxide and germanium oxide with specific atomic ratios and processing conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional wet etching is used for placeholder layer removal, then the etch process can be performed, but selectivity between placeholder layers and dielectric materials deteriorates leading to inconsistent patterning
Solution Approach 1:
The patent changes the material composition parameter of the placeholder layer from silicon nitride to germanium oxide, which fundamentally alters the etch selectivity parameters. This material substitution enables the etch process to achieve both high selectivity against dielectric materials and consistent patterning uniformity, resolving the technical contradiction between reliability and manufacturing precision.
2Ease of manufacture
If silicon nitride placeholder layers are used, then the stacked memory structure can be formed, but temperature sensitivity increases causing layer diffusion during annealing
Solution Approach 1:
The patent changes the thermal stability parameter by substituting silicon nitride with germanium oxide in the placeholder layer. Germanium oxide exhibits superior thermal stability characteristics that prevent layer diffusion during annealing processes, thereby maintaining layer integrity while still enabling stacked memory structure formation.
Solution Approach 2:
The patent employs germanium oxide as a composite material replacement for silicon nitride in the placeholder layer structure. This material substitution provides both the structural functionality needed for stack formation and the thermal stability required to prevent layer diffusion during subsequent annealing processes.
3Productivity
If conventional placeholder materials are used, then the memory structure can be processed, but defect formation increases due to material inconsistencies
Solution Approach 1:
The patent changes the material uniformity parameter by using germanium oxide instead of silicon nitride for placeholder layers. This substitution provides more consistent material properties that reduce processing variability and defect formation, thereby improving both productivity through fewer reworks and reliability through reduced defects.
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 improves the uniformity and selectivity of the etch process, reducing defect formation and maintaining layer integrity, resulting in improved memory hole formation and stack structure uniformity compared to conventional methods.
Implementation Method 1
forming a plasma of the silicon-containing precursor in the processing region and forming a first layer of material on the substrate. The first layer of material may include silicon oxide.
Implementation Method 2
providing a silicon-containing precursor to a processing region of a semiconductor processing chamber... forming a plasma of the silicon-containing precursor in the processing region and forming a first layer of material on the substrate
Implementation Method 3
providing a germanium-containing precursor to the processing region of the semiconductor processing chamber and forming a plasma of the germanium-containing precursor in the processing region. Forming the plasma of the germanium-containing precursor may be performed at a plasma power of greater than or about 500 W
Implementation Method 4
forming a plasma of the germanium-containing precursor in the processing region... forming a second layer of material on the substrate. The second layer of material may include germanium oxide
Implementation Method 5
The methods may further include annealing the substrate subsequent forming alternating sets of the first layer of material and the second layer of material
Data Source
AI summary
Exemplary semiconductor processing methods may include providing a silicon-containing precursor to a processing region of a semiconductor processing chamber. A substrate may be disposed within the processing region of the semiconductor processing chamber. The methods may include forming a plasma of the silicon-containing precursor in the processing region and forming a first layer of material on the substrate. The first layer of material may include silicon oxide. The methods may include providing a germanium-containing precursor to the processing region of the semiconductor processing chamber and forming a plasma of the germanium-containing precursor in the processing region. Forming the plasma of the germanium-containing precursor may be performed at a plasma power of greater than or about 500 W. The methods may include forming a second layer of material on the substrate. The second layer of material may include germanium oxide.