Dielectric Layer Formation Using Metal Silicate Precursors
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Solution Overview
Problem
Semiconductor devices face challenges in maintaining cell capacitance while reducing dielectric layer thickness, which can lead to deteriorated leakage current characteristics, and require a dielectric layer with uniform atom distribution to minimize cell dispersion.
Innovation Solution
A method of forming a dielectric layer using a metal precursor expressed as R3yM(NR1R2)x-y and a silicon precursor expressed as HzSi(NR4R5)4-z, where R1, R2, R3, R4, and R5 denote hydrogen or hydrocarbon, with specific ranges for x, y, and z, and M being a metal from groups III, IV, and V, including lanthanide, to create a metal silicate or nitride layer with alternating sub-layers and thermal treatment for uniform distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the thickness of the dielectric layer is reduced to increase cell capacitance, then the capacitance increases, but the leakage current characteristic deteriorates
Solution Approach 1:
The patent employs composite dielectric layers combining metal oxides (such as HfO2, ZrO2) with silicon oxide or silicon nitride. This composite structure achieves high capacitance through the high-k metal oxide while the silicon-based layer provides excellent leakage current control, thus resolving the contradiction between increasing capacitance and maintaining low leakage current.
Solution Approach 2:
The patent creates dielectric layers with non-uniform composition and varying local properties. By controlling the spatial distribution of metal atoms and silicon atoms through sequential deposition and thermal treatment, the layer achieves high capacitance in certain regions while maintaining low leakage current in other regions, particularly at interfaces.
2Ease of manufacture
If conventional precursors are used for dielectric layer formation, then the deposition process is simple, but the atom distribution uniformity is poor leading to cell dispersion
Solution Approach 1:
The patent modifies precursor parameters by selecting specific metal precursors (such as M(OR1R2) or R3yM(NR1R2)x-y) and silicon precursors (such as HzSi(NR4R5)4-z) with controlled decomposition temperatures. By adjusting deposition temperature, pressure, and precursor flow rates, the patent achieves uniform atomic-level mixing of metal and silicon atoms throughout the dielectric layer, eliminating cell dispersion while maintaining process simplicity.
Solution Approach 2:
The patent performs preliminary surface preparation and precursor adsorption steps before final deposition. The substrate surface is pre-treated to ensure uniform nucleation, and precursors are pre-adsorbed at controlled temperatures to achieve homogeneous atomic distribution before reaction, preventing cell dispersion from the outset.
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 results in a dielectric layer with improved leakage current characteristics and uniform atom distribution, enhancing the capacitance and reliability of semiconductor devices by maintaining thermal stability and constant deposition rates for both precursors.
Implementation Method 1
supplying the silicon precursor to a substrate to adsorb the silicon precursor on a surface of the substrate; and supplying the metal precursor to the substrate to adsorb the metal precursor on the surface of the substrate
Implementation Method 2
supplying an oxygen-containing gas or a nitrogen-containing gas to react the silicon precursor with the oxygen-containing gas or the nitrogen-containing gas, thereby forming the second sub-dielectric layer
Implementation Method 3
supplying an oxygen-containing gas or a nitrogen-containing gas to react the metal precursor with the oxygen-containing gas or the nitrogen-containing gas, thereby forming the second sub-dielectric layer
Implementation Method 4
The thermal treatment may diffuse silicon atoms in the second sub-dielectric layer into the first sub-dielectric layer
Data Source
AI summary
According to example embodiments, a method of forming a layer includes: forming a dielectric layer using a metal precursor expressed by one of R3yM(NR1R2)x-y and M(OR1R2) and using a silicon precursor expressed by HzSi(NR4R5)4-z. Each of “R1”, “R2”, “R3”, “R4”, and “R5” are hydrogen or hydrocarbon; “R3” is different than “R1” and “R2”; “x” is in the range of 3 to 5; “y” is in the range of 1 to 4; “z” is in the range of 2 to 3; and “M” is a metal. The dielectric layer is a metal silicate layer or a metal nitride layer doped with silicon.