ZrO2 Doping with Niobium Precursors for High Dielectric DRAM
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Solution Overview
Problem
Current DRAM capacitors using ZrO2-based dielectrics face challenges in achieving high dielectric constants beyond 40 and require new niobium precursors with high volatility and suitable deposition properties for forming niobium-containing materials.
Innovation Solution
The use of specific titanium, niobium, silicon, and germanium precursors, such as t-BuN═Nb(NEtMe)3, for doping zirconium oxide films and forming niobium-containing films through vapor deposition techniques like ALD and CVD, which provide high volatility and diffusivity, enabling uniform dopant concentration and higher dielectric constants.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional ZrO2-based dielectrics are used in DRAM capacitors, then the dielectric constant can be maintained at moderate levels, but achieving high dielectric constants greater than 40 becomes difficult
Solution Approach 1:
The patent applies parameter changes by systematically varying the dopant composition (Ti, Nb, Si, Ge ratios), deposition temperature, and processing conditions to transform the dielectric properties of ZrO2. By changing the chemical composition parameters through controlled doping, the dielectric constant is elevated from moderate levels to greater than 40, resolving the contradiction between maintaining ease of manufacture and achieving high dielectric constant performance.
Solution Approach 2:
The patent creates composite materials by doping pure ZrO2 with multiple dopants (Ti, Nb, Si, Ge) in specific combinations. This composite approach allows the base ZrO2 matrix to provide structural stability while the dopant elements contribute to enhanced dielectric properties, achieving dielectric constants greater than 40 without fundamentally changing the manufacturing process complexity.
2Manufacturing precision
If new niobium precursors are developed to achieve high volatility and good deposition properties, then uniform dopant concentration and high dielectric constants can be achieved, but the complexity of precursor selection and process optimization increases
Solution Approach 1:
The patent systematically evaluates and optimizes precursor parameters including volatility, reactivity, and deposition characteristics. By changing the chemical structure parameters of the precursors (selecting specific organometallic compounds with appropriate ligands), the patent achieves uniform dopant concentration in the deposited films while managing the complexity through methodical parameter optimization rather than trial-and-error approaches.
Solution Approach 2:
The patent uses organometallic precursor compounds as intermediaries to deliver niobium and other dopants in a controlled manner. These precursor molecules act as mediators between the gaseous phase and the solid film, enabling uniform dopant distribution through their controlled decomposition and reaction during deposition, thereby achieving manufacturing precision while managing process complexity.
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 results in zirconium oxide materials with dielectric constants greater than 40 and superior electrical performance, stabilizing the tetragonal phase and enhancing the properties of DRAM devices.
Implementation Method 1
forming of niobium and niobium-containing films on substrates by vapor deposition such as chemical vapor deposition (CVD), atomic layer deposition (ALD)
Implementation Method 2
chemical vapor deposition (CVD), atomic layer deposition (ALD)
Data Source
AI summary
A method of forming a dielectric material, comprising doping a zirconium oxide material, using a dopant precursor selected from the group consisting of Ti(NMe2)4; Ti(NMeEt)4; Ti(NEt2)4;TiCl4; tBuN═Nb(NEt2)3; tBuN═Nb(NMe2)3; t-BuN═Nb(NEtMe)3; t-AmN═Nb(NEt2)3; t-AmN═Nb(NEtMe)3; t-AmN═Nb(NMe2)3; t-AmN═Nb(OBu-t)3; Nb-13; Nb(NEt2)4; Nb(NEt2)5; Nb(N(CH3)2)5; Nb(OC2H5)5; Nb(thd)(OPr-i)4; SiH(OMe)3; SiCU; Si(NMe2)4; (Me3Si)2NH; GeRax(ORb)4.x wherein x is from 0 to 4, each Ra is independently selected from H or C1-C8 alkyl and each Rb is independently selected from C1-C8 alkyl; GeCl4; Ge(NRa2)4 wherein each Ra is independently selected from H and C1-C8 alkyl; and (Rb3Ge)2NH wherein each Rb is independently selected from C1-C8 alkyl; bis(N,N′-diisopropyl-1,3-propanediamide) titanium; and tetrakis(isopropylmethylamido) titanium; wherein Me is methyl, Et is ethyl, Pr-i is isopropyl, t-Bu is tertiary butyl, t-Am is tertiary amyl, and thd is 2,2,6,6-tetramethyl-3,5-heptanedionate. Doped zirconium oxide materials of the present disclosure are usefully employed in ferroelectric capacitors and dynamic random access memory (DRAM) devices.