Carbon-Doped Hard Mask Structure for Low-Stress Etching
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Solution Overview
Problem
Existing semiconductor masks face challenges in reliability and performance due to increased fabrication complexity as component sizes scale down, leading to issues such as de-bonding, cracking, and bending during etching processes.
Innovation Solution
A semiconductor structure with a hard mask layer doped with a Group IV-A element, specifically carbon, is developed, featuring a ratio of sp3 to sp2 orbital bonds of 2.5-4.0, which reduces compressive stress to -100 to 100 MPa, maintaining etching resistance and preventing de-bonding, cracking, and bending.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If component sizes are scaled down to increase density, then device density improves, but fabrication complexity and reliability worsen
Solution Approach 1:
The patent changes the chemical composition parameters of the hard mask layer by doping with Group IV-A elements (Si, Ge, Sn) at controlled concentrations (10^19 to 10^21 atoms/cm³). This parameter modification adjusts the material properties to maintain reliability during scaling, directly resolving the contradiction between increased density and fabrication reliability.
Solution Approach 2:
The patent creates a composite hard mask layer by combining carbon-based materials with Group IV-A element dopants. This composite structure provides both the etching resistance needed for small feature fabrication and the stress management properties required for reliability, thereby resolving the contradiction between density scaling and fabrication reliability.
2Reliability
If hard mask layer stress is reduced to prevent de-bonding and cracking, then reliability improves, but etching resistance may worsen
Solution Approach 1:
The patent modifies the stress parameter of the hard mask layer by controlling the concentration of Group IV-A element dopants. By adjusting doping levels, the compressive stress is optimized to a specific range that prevents de-bonding and cracking while preserving adequate etching resistance, thus resolving the contradiction between reliability and strength.
Solution Approach 2:
The patent introduces local quality variations within the hard mask layer through controlled doping distributions. The Group IV-A elements are distributed at specific concentrations to create regions with optimized stress characteristics while maintaining overall etching resistance, resolving the contradiction between mask layer stability and etching performance.
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 doped hard mask layer enhances the reliability and stability of semiconductor structures by reducing stress and maintaining etching resistance, improving the performance and process margin of semiconductor devices.
Implementation Method 1
a compressive stress of the hard mask layer doped with the first IV-A element is about -100 MPa to about 100 MPa
Implementation Method 2
a number of sp3 orbital bonds is greater than a number of sp2 orbital bonds of the first IV-A element doped in the hard mask layer, a ratio of a number of sp3 orbital bonds to a number of sp2 orbital bonds of the first IV-A element doped in the hard mask layer is 2.5-4.0
Data Source
AI summary
A semiconductor structure is provided. The semiconductor structure includes a substrate, a target layer on the substrate, and a hard mask layer doped with a group IV-A element on the target layer. The number of sp3 orbital bonds in the hard mask layer is greater than the number of sp2 orbital bonds.