Bulk Precursor Vaporization With Heated Baffles for Uniform Dosing

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Solution Overview

Problem

Existing substrate processing systems face challenges in achieving uniform vaporization and accurate dosing of liquid precursors, as current methods like bubblers and evaporators result in variable vapor concentrations and potential droplet formation, making it difficult to deliver a consistent and droplet-free vaporized precursor to substrates.

Innovation Solution

A vaporization system featuring a bubbler portion with a baffle portion containing multiple heated baffles, where each baffle has a temperature sensor and heater, controlled by a controller to maintain varying temperatures, and a porous medium to distribute carrier gas uniformly, ensuring vaporization occurs in the saturated region and minimizing droplet formation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If a bubbler is used to vaporize liquid precursor, then the liquid precursor can be vaporized and carried away with carrier gas, but the vapor concentration becomes variable and droplets/foam form

Engineering Contradiction:

Improvevapor concentrationVSAvoidvapor concentration uniformity

Core Design Contradiction:

Quantity of substanceVSManufacturing precision

Solution Approach 1:

The patent employs a porous plug or porous frit at the bottom of the bubbler to distribute carrier gas uniformly across the liquid precursor surface. This creates numerous small, consistent bubble streams that ensure uniform vaporization and prevent localized pooling, foam formation, and droplet generation, thereby achieving consistent vapor concentration.

Inventive Principle:

Principle #31Porous materials

Solution Approach 2:

The patent replaces the mechanical bubbling action (which causes variable exposure and droplet formation) with a controlled gas distribution system through porous materials. This substitution allows precise control of gas flow distribution and vaporization conditions, eliminating the mechanical instability that causes concentration variations.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Manufacturing precision

If an evaporator is used to vaporize liquid precursor, then the vapor concentration can be controlled, but the low flow rate is difficult to meter and deliver accurately

Engineering Contradiction:

Improvevapor concentration controlVSAvoidflow rate delivery accuracy

Core Design Contradiction:

Manufacturing precisionVSProductivity

Solution Approach 1:

The patent segments the vaporization process into distinct functional zones: a bubbler portion for bulk vaporization and a baffle portion with multiple heated baffles for sequential processing. This segmentation allows the system to handle higher flow rates in the bubbler while maintaining precise concentration control through the staged baffles, each contributing to uniform vapor delivery.

Inventive Principle:

Principle #1Segmentation

3Ease of operation

If a liquid delivery system with capillary tube is used, then the liquid flow can be controlled, but blockage and bubbles form causing vapor delivery concentration to vary

Engineering Contradiction:

Improveliquid flow controlVSAvoidvapor delivery consistency

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The patent extracts the problematic capillary tube liquid delivery system and replaces it with a bubbler-based vaporization system. By eliminating the narrow capillary passage that is prone to blockage and bubble formation, the system achieves more reliable and consistent vapor delivery while maintaining ease of operation through the bubbler's straightforward liquid level and gas flow control.

Inventive Principle:

Principle #2Taking out (Extraction)

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 system achieves a uniform concentration of vaporized precursor by operating in the saturated region, reducing defects and improving control over vapor concentration, ensuring consistent delivery to substrate processing systems.

Implementation Method 1

a first heated baffle 308-1 having a first temperature less than a second temperature of a second heated baffle 308-2 arranged immediately adjacent to the first heated baffle 308-1

Methodology Applied

Scientific EffectEvaporation: Evaporation

Implementation Method 2

each baffle has a temperature sensor and heater, controlled by a controller to maintain varying temperatures

Methodology Applied

Scientific EffectHeating: Heating

Implementation Method 3

a porous medium to distribute carrier gas uniformly

Methodology Applied

Scientific EffectPorosity: Porosity

Implementation Method 4

each of the N heated baffles comprises a temperature sensor and a heater

Methodology Applied

Scientific EffectTemperature sensing: Thermocouple

Data Source

PatentUS9964332B2Systems and methods for bulk vaporization of precursor

Publication Date: 2018.05.08 LAM RES CORP

AI summary

A vaporization system for liquid precursor includes a bubbler portion configured to store liquid precursor and to supply carrier gas into the liquid precursor to vaporize the liquid precursor to generate vaporized precursor. A baffle portion is arranged in fluid communication with the bubbler portion and includes N heated baffles, where N is an integer greater than or equal to one. The vaporized precursor generated by the bubbler portion passes through the N heated baffles before flowing to a substrate processing system.