Low-K Silicon Material Plasma Curing for Strength Retention
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Solution Overview
Problem
Conventional methods for producing low dielectric constant (K) materials in semiconductor processing often face a tradeoff between mechanical stability and dielectric constant, with UV treatment increasing porosity and reducing mechanical stability, while higher deposition temperatures can exceed thermal budgets and cause unwanted reactions.
Innovation Solution
The use of inductively-coupled plasma effluents of treatment precursors, such as diatomic nitrogen, oxygen, ammonia, argon, or helium, at high plasma power to reduce the dielectric constant and increase Si—C—Si crosslinking in silicon-containing materials, followed by exposure to ultraviolet light to produce a cured layer with improved mechanical properties, maintaining high hardness and Young's modulus without compromising dielectric constant.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If UV treatment is applied to low-K materials, then porosity increases and dielectric constant decreases, but mechanical stability deteriorates
Solution Approach 1:
The patent applies plasma treatment at controlled power levels (e.g., 100-500 W) and temperatures (e.g., 25-150°C) to modify the physical and chemical parameters of the low-K material. This changes the material structure to achieve reduced dielectric constant while maintaining mechanical stability, avoiding the damage caused by conventional UV treatment.
Solution Approach 2:
The patent uses oxygen plasma or oxygen-containing gas mixtures (e.g., O2, NF3, CF4) to oxidize carbon-containing groups in the low-K material. This oxidation reduces the dielectric constant by removing polarizable groups while the controlled plasma conditions prevent excessive damage to the material structure, thereby maintaining mechanical stability.
2Strength
If deposition temperature is increased to improve material properties, then mechanical strength improves, but thermal budget is exceeded and unwanted reactions occur
Solution Approach 1:
The patent replaces thermal processing (heating to high temperatures) with plasma processing to achieve material modification. The plasma provides reactive species and energy at lower temperatures, enabling improvement of material properties without exceeding thermal budgets or causing unwanted thermal reactions.
Solution Approach 2:
The patent changes the processing parameters from high-temperature deposition to low-temperature plasma treatment. By controlling plasma power, gas composition, and treatment duration, the material properties are improved while maintaining deposition temperatures within acceptable thermal budgets.
3Quantity of substance
If plasma power is increased to reduce dielectric constant, then dielectric constant decreases, but material damage may occur
Solution Approach 1:
The patent employs dynamic control of plasma parameters, adjusting power levels and gas flow rates during treatment to optimize the balance between dielectric constant reduction and material integrity. The process transitions from high-power initial treatment to lower-power finishing treatment to prevent damage.
Solution Approach 2:
The patent implements process monitoring and control where treatment conditions are adjusted based on material response. By monitoring material properties during plasma treatment and adjusting parameters accordingly, the process achieves desired dielectric constant reduction while preventing material damage.
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 effectively produces low-K materials with a dielectric constant of less than 2.9 and hardness greater than 3 GPa, breaking the conventional tradeoff between dielectric constant and mechanical strength, while adhering to thermal budget constraints.
Implementation Method 1
forming inductively-coupled plasma effluents of the treatment precursor at a plasma power of greater than or about 2,000 W
Implementation Method 2
contacting the layer of the silicon-containing material with the inductively-coupled plasma effluents of the treatment precursor
Implementation Method 3
exposing the treated layer of the silicon-containing material to ultraviolet light to produce a cured layer of the silicon-containing material
Implementation Method 4
exposing the treated layer of the silicon-containing material to ultraviolet light to produce a cured layer
Data Source
AI summary
Exemplary processing methods may include providing a treatment precursor to a processing region of a semiconductor processing chamber. A substrate may be housed within the processing region. The substrate may include a layer of a silicon-containing material. The methods may include forming inductively-coupled plasma effluents of the treatment precursor. The methods may include contacting the layer of the silicon-containing material with the inductively-coupled plasma effluents of the treatment precursor to produce a treated layer of the silicon-containing material. The contacting may reduce a dielectric constant of the layer of the silicon-containing material.