Cyclic Boron Nitride Film Deposition for Low-k Interconnect Barriers
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The miniaturization of semiconductor devices is limited by increased resistance of interconnects and capacitance delay, and existing boron nitride films exhibit poor thermo-mechanical properties and stability, making it difficult to achieve low-k dielectric and diffusion barrier materials.
Innovation Solution
A cyclic deposition method using a boron precursor with specific halogen groups and plasma-enhanced chemical vapor deposition (PECVD) or plasma-enhanced atomic layer deposition (PEALD) processes to form boron nitride films with low dielectric constants and low wet etch rates, including sub-cycles of deposition and curing plasma.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If low-κ SiCO materials are used to achieve low dielectric constants, then the dielectric constant is reduced, but the thermo-mechanical properties deteriorate
Solution Approach 1:
The patent changes the material composition parameters by using boron nitride with specific stoichiometric ratios (BN, B1.5N, B2N3, B3N4) to achieve low dielectric constants while maintaining excellent thermo-mechanical stability. The cyclic deposition process parameters (temperature, pressure, gas flow rates) are optimized to control film density and properties, resolving the contradiction between low-k requirement and thermo-mechanical reliability
Solution Approach 2:
The patent creates composite-like structures through cyclic deposition of boron nitride films with controlled porosity and density variations. The process alternates between deposition and curing cycles to create films with optimized microstructure that combines low dielectric constant with high mechanical strength and thermal stability
2Ease of manufacture
If conventional deposition methods are used to form boron nitride films, then the process is simpler, but the film stability deteriorates
Solution Approach 1:
The deposition process is segmented into multiple cyclic steps: precursor introduction, plasma activation, deposition, and curing phases. Each cycle deposits a thin layer that is then cured before the next cycle begins. This segmentation allows precise control over film formation and stabilization, dramatically improving film stability compared to conventional single-step deposition methods
Solution Approach 2:
The patent employs periodic cyclic deposition where the substrate undergoes repeated cycles of precursor exposure and plasma treatment. This periodic action ensures uniform film growth and progressive stabilization, creating highly stable boron nitride films with controlled properties that cannot be achieved through continuous deposition
3Object-generated harmful factors
If amorphous boron nitride is used to achieve low dielectric constant and diffusion barrier properties, then the electrical properties are improved, but the thermal stability deteriorates
Solution Approach 1:
The patent controls the deposition temperature, plasma power, and cyclic process parameters to deposit amorphous boron nitride films with optimized microstructure. By adjusting these parameters, the films achieve low dielectric constants for reduced capacitance delay while simultaneously attaining high thermal stability through controlled density and porosity during the cyclic 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 method produces boron nitride films with dielectric constants less than 3.5, wet etch rates less than 0.2 Å/min, and leakage values less than 3e-8 A/cm², enhancing stability and electrical properties.
Implementation Method 1
providing a deposition plasma gas into the reaction chamber and generating a deposition plasma
Implementation Method 2
cyclical plasma-enhanced chemical vapor deposition (PECVD) process
Implementation Method 3
providing a curing plasma gas into the reaction chamber, and generating a curing plasma
Data Source
AI summary
Methods for depositing a boron nitride film on a substrate are disclosed. More particularly, the disclosure relates to methods that can be used for depositing a boron nitride film by a PECVD process. The method comprises providing a substrate into a reaction chamber, and executing a cyclical deposition process comprising a plurality of deposition cycles, ones from the plurality of deposition cycles including providing a boron precursor into the reaction chamber and providing a deposition plasma gas into the reaction chamber.