Mo-Doped Hardmask Films for High-Selectivity 3D Memory Etching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing semiconductor processing technologies face challenges in achieving high etch selectivity for high aspect ratio features, particularly in 3D memory applications, where current hardmask films do not adequately support advanced feature scaling.
Innovation Solution
The use of molybdenum (Mo)-containing layers deposited through plasma-enhanced chemical vapor deposition (PECVD) processes, which can function as hardmasks, intermediate layers, or coverage layers, providing improved etch selectivity and extending technology scaling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional hardmask films are used for etching high aspect ratio features, then the etching process can be performed, but the etch selectivity is insufficient for advanced feature scaling
Solution Approach 1:
The patent applies parameter changes by doping the hardmask film with specific elements (such as tungsten, molybdenum, or tantalum) at controlled concentrations (0.1-10 at%). This changes the chemical composition parameters of the hardmask material, resulting in improved etch selectivity against underlying layers while maintaining the necessary mechanical properties for high aspect ratio feature fabrication
Solution Approach 2:
The patent employs composite materials by creating a hardmask film that combines a base material (such as silicon oxide or silicon nitride) with dopant elements (tungsten, molybdenum, or tantalum). This composite structure provides both the structural integrity needed for high aspect ratio features and the enhanced etch selectivity required for advanced scaling, resolving the contradiction between reliability and manufacturing precision
2Manufacturing precision
If the hardmask film composition is modified to improve etch selectivity, then etching performance improves, but the film deposition process becomes more complex
Solution Approach 1:
The patent merges the hardmask formation and doping steps into a single atomic layer deposition (ALD) process. By co-depositing the base material and dopant elements in one sequential ALD cycle, the process avoids the complexity of separate deposition and doping steps, thereby improving etch selectivity without significantly increasing process complexity
Solution Approach 2:
The patent utilizes parameter changes in the ALD process by adjusting deposition temperature, precursor flow rates, and pulse durations to control the dopant concentration within the hardmask film. This precise parameter control enables tuning of etch selectivity while maintaining a relatively simple single-step deposition process
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
The Mo-containing layers enhance etch selectivity, allowing for precise pattern transfer and improved substrate processing, particularly in 3D memory applications.
Implementation Method 1
depositing by a plasma enhanced chemical vapor deposition (PECVD) process the Mo-containing layer on a surface portion of the substrate
Implementation Method 2
exposing a top surface portion of the substrate to a metal-containing precursor (e.g., a Mo-containing precursor) and one or more optional deposition precursors; and depositing a metal-containing layer (e.g., a Mo-containing layer) on the top surface portion of the substrate in a presence or an absence of a plasma
Data Source
AI summary
The present disclosure relates to high selectivity doped hardmask films, as well as methods of providing and using such films. In particular examples, the high selectivity doped hardmask film can be employed as a hardmask, an intermediate layer, or a coverage layer.