SiGe:B Layer Deposition with Staged Boron Flow at Interfaces

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Solution Overview

Problem

Existing semiconductor deposition methods face challenges in managing disparate incorporation affinities and migration tendencies of constituents like boron, leading to potential boron accumulation at interfaces, which can alter the electrical properties of semiconductor structures.

Innovation Solution

A method involving the controlled mass flow rate of a boron-containing precursor during the deposition of SiGe:B layers, where the mass flow rate is increased in stages to limit boron concentration at the interface between the first and second SiGe:B layers, ensuring it remains less than the concentration within the second layer.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the mass flow rate of boron-containing precursor is increased to deposit the second SiGe:B layer, then the deposition speed increases, but boron accumulates at the interface between the first and second layers

Engineering Contradiction:

Improvedeposition speedVSAvoidboron concentration control at interface

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The patent applies dynamics by making the mass flow rate of the boron-containing precursor variable rather than constant. The flow rate is dynamically adjusted through three distinct stages: an initial rate during deposition of the first SiGe:B layer, an intermediate rate during deposition of the second SiGe:B layer, and a final rate after the second layer is deposited. This dynamic adjustment prevents boron accumulation at the interface while maintaining efficient deposition.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent applies preliminary action by establishing a specific deposition sequence and pre-defining the mass flow rate stages before deposition begins. The method pre-establishes that the intermediate mass flow rate will be used during the critical phase of second layer deposition to prevent interface contamination, ensuring proper boron concentration control is in place before the deposition process starts.

Inventive Principle:

Principle #10Preliminary action

2Manufacturing precision

If deposition is interrupted to prevent boron accumulation at the interface, then boron concentration control improves, but the deposition process time increases

Engineering Contradiction:

Improveboron concentration control at interfaceVSAvoiddeposition process time

Core Design Contradiction:

Manufacturing precisionVSLoss of time

Solution Approach 1:

The patent applies continuity of useful action by maintaining continuous deposition throughout the entire process without interruptions. The mass flow rate is continuously adjusted through the three stages, but the deposition itself never stops. This eliminates idle time between layers while still achieving precise boron concentration control at the interface through the intermediate flow rate stage.

Inventive Principle:

Principle #20Continuity of useful action

Solution Approach 2:

The dynamic adjustment of mass flow rate allows the process to maintain continuity while adapting to different deposition phases. The system transitions smoothly between flow rate stages without stopping, enabling continuous operation with precise control over boron incorporation at critical interfaces.

Inventive Principle:

Principle #15Dynamics

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 prevents boron accumulation at the interface, maintaining the desired electrical properties of the semiconductor structure and allowing for continuous deposition without interruptions, thus enhancing the reliability and efficiency of the semiconductor fabrication process.

Implementation Method 1

flowing a boron-containing precursor to the chamber arrangement at a first boron-containing precursor mass flow rate, and depositing a first portion of a first SiGe:B layer using the boron-containing precursor

Methodology Applied

Scientific EffectChemical Vapour Deposition: Chemical Vapour Deposition

Data Source

PatentUS20250079167A1Methods of forming semiconductor structures, semiconductor processing systems and related computer program products

Publication Date: 2025.03.06 ASM IP HLDG BV

AI summary

A method of forming a semiconductor structure includes seating a substrate on a substrate support arranged within a chamber arrangement of a semiconductor processing system, flowing a boron-containing precursor to the chamber arrangement at a first boron-containing precursor mass flow rate, and depositing a first portion of a first SiGe:B layer using the boron-containing precursor. Mass flow rate of the boron-containing precursor to an intermediate boron-containing precursor flow rate, a second portion of the first SiGe:B layer is deposited using the boron-containing precursor, mass flow rate of the boron-containing precursor to the chamber arrangement is further increased to a second boron-containing precursor mass flow rate, and a second SiGe:B layer is deposited onto the first SiGe:B layer using the boron-containing precursor, the increase in the mass flow rate of the boron-containing precursor to the intermediate boron-containing precursor mass flow rate limits boron concentration at a first SiGe:B layer-to-second SiGe:B layer interface defined between the first SiGe:B layer and the second SiGe:B layer to less than a boron concentration within the second SiGe:B layer. Semiconductor processing systems and related computer program products are also provided.