Pulsed RF Low-k Film Deposition for Strength and Dielectric Balance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional deposition methods for low-k films using continuous RF power result in films with undesirable mechanical strength and dielectric constant properties.
Innovation Solution
The method involves pulsing RF power during the deposition of low-k films in a semiconductor processing chamber, using a silicon-containing precursor and maintaining specific conditions such as pulsing frequency, duty cycle, temperature, and pressure to achieve a denser film with improved mechanical strength and low dielectric constant.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If continuous RF power is used during deposition, then the deposition process is simple and continuous, but the resulting low-k film has poor mechanical strength
Solution Approach 1:
The patent applies periodic action by pulsing the RF power during deposition instead of using continuous RF power. The RF power is applied in pulses with specific duty cycles (e.g., 10-90%) and frequencies (e.g., 1-50 kHz), creating periodic plasma conditions that enhance film density and mechanical strength while maintaining the low-k property. This periodic modulation of power resolves the contradiction by transforming a simple continuous process into a controlled periodic process that achieves superior mechanical properties.
2Strength
If higher ion density is achieved to increase mechanical strength, then the film becomes denser with better mechanical properties, but the dielectric constant increases
Solution Approach 1:
The periodic pulsing of RF power creates alternating high-ion-density and low-ion-density phases during deposition. During the RF-on phase, high ion density promotes dense film growth and strong bonding. During the RF-off phase, ion density decreases, allowing volatile byproducts to evacuate and preventing excessive crosslinking that would increase dielectric constant. This temporal separation resolves the contradiction between mechanical strength and dielectric constant.
Solution Approach 2:
The patent changes the temporal parameters of RF power delivery by introducing pulse width, duty cycle, and frequency parameters. By optimizing these parameters (e.g., duty cycle of 10-90%, frequency of 1-50 kHz), the process controls the average ion density and energy deposition rate, achieving a balance where sufficient ion density provides mechanical strength while controlled average density maintains low dielectric constant.
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 increases the ion density in the plasma, resulting in a denser material with higher mechanical strength and maintaining a low dielectric constant, characterized by hardness and Young's modulus values greater than conventional methods.
Implementation Method 1
forming a plasma of the silicon-containing precursor in the processing region. The plasma may be at least partially formed by a pulsing RF power operating at less than or about 2,000 W
Implementation Method 2
The plasma may be at least partially formed by a pulsing RF power operating at a pulsing frequency less than or about 50,000 Hz
Implementation Method 3
forming a layer of silicon-containing material on the substrate. The layer of silicon-containing material may be characterized by a dielectric constant less than or about 3.0
Implementation Method 4
providing a silicon-containing precursor to a processing region of a semiconductor processing chamber... forming a layer of silicon-containing material on the substrate
Implementation Method 5
The methods may include curing the layer of silicon-containing material on the substrate by directing ultraviolet (UV) energy towards the substrate
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. The plasma may be at least partially formed by a pulsing RF power operating at less than or about 2,000 W. The methods may include forming a layer of silicon-containing material on the substrate. The layer of silicon-containing material may be characterized by a dielectric constant less than or about 3.0.