TEMAT Precursor TiN Deposition for High Rate Conformal Films

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Solution Overview

Problem

Existing deposition methods for titanium nitride (TiN) films in semiconductor manufacturing face challenges such as poor step coverage over high-aspect ratio features, low deposition rates, and contamination issues, which hinder their suitability for advanced semiconductor devices.

Innovation Solution

A chemical vapor deposition (CVD) process using tetrakis(ethylmethylamino) titanium (TEMAT) precursor vapor at high gas flow rates and low process chamber pressures, combined with cyclical deposition methods, to achieve conformal TiN films with improved step coverage and higher deposition rates, while minimizing impurity incorporation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional CVD methods using TiCl4 and NH3 are used, then deposition rate is high, but chlorine contamination occurs and processing temperature must be high (500-700°C)

Engineering Contradiction:

Improvedeposition rateVSAvoidchlorine contamination

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent changes the chemical parameters by replacing TiCl4 with TEMAT precursor and NH3 with N2O, transforming the deposition chemistry to eliminate chlorine-containing reaction pathways while maintaining high deposition rates through optimized gas flow rates and pressure conditions

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent uses disposable precursor molecules (TEMAT and N2O) that decompose completely during deposition, leaving no residual contamination on the substrate, unlike chlorine-based processes where chlorine can diffuse into and permanently contaminate the semiconductor substrate

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

2Manufacturing precision

If ALD methods are used, then film conformality and step coverage are improved, but deposition rate becomes very low (1-2 Å per cycle)

Engineering Contradiction:

Improvefilm conformalityVSAvoiddeposition rate

Core Design Contradiction:

Manufacturing precisionVSProductivity

Solution Approach 1:

The patent employs periodic pulsing of precursor gases (TEMAT followed by N2O) in a cyclic manner, allowing each precursor to react completely before the next is introduced, maintaining conformal deposition while achieving much higher net deposition rates than traditional ALD through optimized pulse durations and frequencies

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The patent changes key process parameters including operating pressure (0.1-10 Torr), gas flow rates (50-500 sccm), and temperature (200-400°C) to optimize the balance between film conformality and deposition rate, deviating from both conventional CVD and standard ALD parameter ranges

Inventive Principle:

Principle #35Parameter changes

3Productivity

If chlorine-based CVD processes are used, then deposition rate is high, but processing temperature must be high (500-700°C) which may damage underlying structures

Engineering Contradiction:

Improvedeposition rateVSAvoidprocessing temperature

Core Design Contradiction:

ProductivityVSTemperature

Solution Approach 1:

The patent changes the chemical composition of precursors to TEMAT and N2O, which have lower decomposition temperatures than TiCl4-based chemistry, enabling high-rate deposition at reduced temperatures (200-400°C) that are compatible with temperature-sensitive semiconductor structures

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent uses TEMAT as an intermediary titanium source that decomposes at lower temperatures than TiCl4, acting as a mediator that enables titanium nitride deposition without requiring the high temperatures necessary for conventional chloride-based CVD processes

Inventive Principle:

Principle #24Intermediary (Mediator)

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 approach enables high-volume manufacturing of semiconductor devices with conformal TiN films that have good step coverage and high deposition rates, reducing impurity levels and enhancing the quality of TiN films for advanced semiconductor applications.

Implementation Method 1

a chemical vapor deposition (CVD) process using high gas flow rate of a tetrakis(ethylmethylamino) titanium (TEMAT) precursor vapor

Methodology Applied

Scientific EffectChemical Vapour Deposition: Chemical Vapour Deposition

Implementation Method 2

decomposition of the TEMAT precursor on a heated substrate

Methodology Applied

Scientific EffectThermolysis: Thermolysis

Implementation Method 3

heating the substrate to a temperature greater than 200° C. and less than 400° C.

Methodology Applied

Scientific EffectHeating: Heating

Data Source

PatentUS7776733B2Method for depositing titanium nitride films for semiconductor manufacturing

Publication Date: 2010.08.17 TOKYO ELECTRON LTD

AI summary

Embodiments of the invention describe TiN deposition methods suitable for high volume manufacturing of semiconductor devices on large patterned substrates (wafers). One embodiment describes a chemical vapor deposition (CVD) process using high gas flow rate of a tetrakis(ethylmethylamino) titanium (TEMAT) precursor vapor along with an inert carrier gas at a low process chamber pressure that provides high deposition rate of conformal TiN films with good step coverage in surface reaction limited regime. Other embodiments describe cyclical TiN deposition methods using TEMAT precursor vapor and a nitrogen precursor.