Cyclic Dielectric Recess Filling to Prevent Void Formation
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Solution Overview
Problem
Existing methods for filling recesses in substrates during electronic device manufacturing often result in void formation, which compromises device isolation and structural integrity, and are limited by size constraints that reduce device packing density.
Innovation Solution
A cyclic deposition method and apparatus that inhibits material deposition at the top of recesses relative to the bottom, using a sequence of reactants to form active and chemisorbed species under controlled pressure and temperature conditions, facilitating seamless filling of high-aspect ratio recesses with low-temperature deposition and minimizing oxidation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional recess filling methods are used, then the recess can be filled with material, but void formation occurs that compromises device isolation and structural integrity
Solution Approach 1:
The patent applies periodic action by using cyclic deposition sequences with alternating reactant pulses (e.g., TMHDO and O3) to fill recesses. The cyclic process allows controlled material deposition in stages, preventing void formation while maintaining device isolation and structural integrity through repeated deposit-purge cycles.
Solution Approach 2:
The patent employs parameter changes by varying deposition conditions including temperature (200-450°C range), pressure conditions, and reactant pulse timing to optimize material deposition. These parameter adjustments enable seamless filling of recesses without voids while maintaining high-quality dielectric material properties.
2Manufacturing precision
If recess depth is decreased to prevent void formation, then voids are reduced, but device isolation effectiveness is reduced
Solution Approach 1:
The cyclic deposition method enables complete filling of deep recesses by using repeated deposit-purge cycles, eliminating the need to decrease recess depth. The periodic reactant pulsing ensures material reaches the bottom of deep recesses while preventing void formation, maintaining both device isolation effectiveness and manufacturing precision.
Solution Approach 2:
The patent uses preliminary action by introducing reactants in controlled sequences that prepare the recess surface for subsequent deposition steps. The first reactant pulse modifies the surface, and subsequent pulses build material layer by layer, ensuring complete filling of deep recesses without voids while maintaining isolation effectiveness.
3Manufacturing precision
If recess top openings are enlarged to prevent void formation, then voids are reduced, but IC real estate is increased
Solution Approach 1:
The cyclic deposition process fills recesses with vertical sidewalls completely without voids by using controlled reactant pulsing sequences. This eliminates the need to enlarge recess top openings, maintaining compact IC real estate while achieving void-free filling through repeated deposit-purge cycles.
Solution Approach 2:
The patent uses parameter changes in deposition temperature and reactant pulse timing to achieve seamless filling of recesses with standard dimensions. By optimizing these parameters, the process fills recesses completely without voids while maintaining the original compact IC footprint.
4Manufacturing precision
If high-temperature deposition is used to improve material quality, then material quality improves, but oxidation of underlying and surrounding material occurs
Solution Approach 1:
The patent uses parameter changes by optimizing deposition temperature to the 200-450°C range and controlling reactant exposure timing. This produces high-quality dielectric material with appropriate density and conformality while preventing oxidation of underlying and surrounding substrate materials through controlled thermal exposure.
Solution Approach 2:
The cyclic deposition process with alternating reactant pulses allows brief, controlled exposure to reactive species at moderate temperatures. This periodic exposure builds high-quality material layers while limiting total thermal exposure time, preventing oxidation of surrounding materials.
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 and apparatus enable seamless filling of high-aspect ratio recesses with high-quality dielectric material, preventing void formation and reducing the need for post-treatment annealing, thereby improving device isolation and packing density.
Implementation Method 1
introducing a first reactant, to form first active species, for a first pulse time to the substrate at a first pressure, wherein the first active species modify a first portion (e.g., top) of a surface of the recess
Implementation Method 2
introducing a second reactant for a second pulse time to the substrate, wherein the second reactant reacts with a second portion (e.g., bottom) of the surface of the recess to form chemisorbed material on the second portion
Implementation Method 3
introducing a third reactant, to form second active species, for a third pulse time to the substrate at a second pressure, wherein the second active species react with the chemisorbed material to form deposited material
Implementation Method 4
an anisotropic plasma can be formed during the step of introducing a first reactant. And, in accordance with yet further examples, an isotropic plasma can be formed during the step of introducing a third reactant
Data Source
AI summary
There is provided a method of filling one or more recesses by providing the substrate in a reaction chamber; introducing a first reactant, to form first active species, for a first pulse time to the substrate; introducing a second reactant for a second pulse time to the substrate; and introducing a third reactant, to form second active species, for a third pulse time to the substrate. An apparatus for filling a recess is also disclosed and a structure formed using the method and/or apparatus is disclosed.