Cc-Structure Ternary Paraelectric for Low-Leakage DRAM Dielectrics
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Solution Overview
Problem
As semiconductor devices integrate more densely, the thinning of dielectric materials in DRAM increases the likelihood of leakage current, necessitating a dielectric with a high dielectric constant and minimized leakage effects.
Innovation Solution
Development of ternary paraelectrics with a monoclinic Cc structure, specifically A2B4O11 materials, which have a high dielectric constant of 150 to 250 and a bandgap energy greater than SrTiO3, manufactured using methods involving precursor mixing, planetary milling, calcining, cold isostatic pressing, spark plasma sintering, and re-heat treatment to achieve a relative density of 90% or more.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the thickness of the dielectric is reduced to increase integration density, then the capacitance increases, but the leakage current increases
Solution Approach 1:
The patent changes the material parameters by developing a new paraelectric material composition (A2B4O11 system) with specific crystal structure (Cc space group) to achieve high dielectric constant while maintaining low leakage current, resolving the contradiction between thinning for integration and preventing leakage
Solution Approach 2:
The patent uses composite material approach by creating a ternary paraelectric material system (A2B4O11 where A is Group 1 element and B is Group 5 element) that combines multiple elements to achieve superior dielectric properties that single materials cannot provide, specifically high dielectric constant with low leakage
2Reliability
If the dielectric constant is increased to maintain capacitance, then the capacitance increases, but the material complexity increases
Solution Approach 1:
The patent systematically varies compositional parameters (A and B element selection) and crystal structure parameters (Cc space group) to optimize dielectric constant while managing material complexity, achieving K=150-250 through controlled parameter adjustment
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 ternary paraelectrics effectively reduce leakage current while maintaining high dielectric constant values, stabilizing the operation of highly integrated DRAM and enhancing semiconductor device reliability.
Implementation Method 1
a dielectric constant of 150 to 250
Implementation Method 2
a bandgap energy greater than that of SrTiO3 (STO)
Implementation Method 3
The sintering may comprise a spark plasma sintering (SPS) operation
Data Source
AI summary
A ternary paraelectric having a Cc structure and a method of manufacturing the same are provided. The ternary paraelectric having a Cc structure includes a material having a chemical formula of A2B4O11 that has a monoclinic system, is a space group No. 9, and has a dielectric constant of 150 to 250, wherein “A” is a Group 1 element, and “B” is a Group 5 element. “A” may include one of Na, K, Li and Rb. “B” may include one of Nb, V, and Ta. The A2B4O11 material may be Na2Nb4O11 in which bandgap energy thereof is greater than that of STO. The A2B4O11 material may have relative density that is greater than 90% or more.