Zoned Shower Head Holes for Low-Pressure PECVD Arcing Control

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Solution Overview

Problem

Arcing occurs in plasma-enhanced chemical vapor deposition (PECVD) processes due to charge accumulation at the edge of the shower head, leading to micro particle contamination, electrical damage, and frequent replacement of the shower head, especially during low-pressure operations for low-k dielectric film deposition.

Innovation Solution

A modified shower head structure with a plurality of second through holes near the edge, having a reduced diameter compared to the first through holes at the center, to prevent arcing by reducing the sheath layer formation and charge accumulation, maintaining gas flow and compatibility with current PECVD processes without altering process parameters.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If the shower head uses uniform through holes for gas distribution, then the gas flow distribution is simple and manufacturing is easy, but charge accumulation occurs at the edge leading to arcing

Engineering Contradiction:

Improveshower head manufacturing simplicityVSAvoidshower head operational reliability

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The patent applies local quality by making the through holes non-uniform: holes in the first zone (center region) have a first diameter, while holes in the second zone (edge region) have a second diameter that is different from the first. This local variation in hole diameter prevents charge accumulation at the edge while maintaining manufacturing feasibility, thereby resolving the contradiction between manufacturing simplicity and operational reliability.

Inventive Principle:

Principle #3Local quality

2Manufacturing precision

If the shower head operates at low pressure for low-k dielectric deposition, then deposition quality is improved, but arcing occurs more frequently due to charge accumulation

Engineering Contradiction:

Improvelow-k dielectric deposition qualityVSAvoidarcing and micro particle contamination

Core Design Contradiction:

Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The patent uses local quality by creating zones with different hole diameters: the first zone (center) has holes with a first diameter optimized for deposition quality, while the second zone (edge) has holes with a second diameter that prevents charge accumulation and arcing. This allows low-pressure operation for high-quality low-k dielectric deposition without the harmful arcing effects.

Inventive Principle:

Principle #3Local quality

3Reliability

If the shower head through holes are reduced in diameter to prevent arcing, then charge accumulation is reduced, but gas flow distribution may be affected

Engineering Contradiction:

Improvearcing preventionVSAvoidgas flow through holes

Core Design Contradiction:

ReliabilityVSQuantity of substance

Solution Approach 1:

The patent applies local quality by reducing hole diameter only in the second zone (edge region) while maintaining larger holes in the first zone (center region). This localized reduction prevents charge accumulation and arcing at the edge where the problem occurs, while preserving adequate gas flow through the center holes, thus resolving the contradiction between arcing prevention and gas flow maintenance.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent segments the shower head into two distinct zones with different hole characteristics: the first zone with holes of a first diameter and the second zone with holes of a second diameter. This segmentation allows different regions to be optimized for different functions - the center for gas flow and the edge for preventing charge accumulation - thereby resolving the contradiction between preventing arcing and maintaining gas flow.

Inventive Principle:

Principle #1Segmentation

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 solution effectively prevents arcing inside the shower head holes, extending the lifetime of the shower head, reducing downtime and maintenance costs, and ensuring consistent deposition and etching processes without altering existing process parameters.

Implementation Method 1

Plasma-enhanced chemical vapor deposition (PECVD) process is widely used in the semiconductor industry

Methodology Applied

Scientific EffectPlasma: Plasma

Implementation Method 2

chemical vapor deposition (CVD) process

Methodology Applied

Scientific EffectChemical vapor deposition: Chemical Vapour Deposition

Data Source

PatentUS11859284B2Shower head structure and plasma processing apparatus using the same

Publication Date: 2024.01.02 TAIWAN SEMICONDUCTOR MANUFACTURING CO LTD

AI summary

A shower head structure and a plasma processing apparatus are provided. The shower head structure includes a plate body with a first zone and a second zone on a first surface. A plurality of first through holes are in the first zone, each of the first through holes having a diameter uniform with others of the first through holes. A plurality of second through holes are in the second zone. The first zone is in connection with the second zone, and the diameter of each of the first through holes is greater than a diameter of each of the second through holes. A plasma processing apparatus includes the shower head structure is also provided.