BEOL MIM Capacitor Phase Transition for High Dielectric Constant
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Advanced semiconductor technologies face challenges in achieving high capacitance for on-chip metal-insulator-metal decoupling capacitors (MIMCAPs) while maintaining low leakage current, due to limitations in the thermal budget and dielectric constant of materials like HfO2 and ZrO2 when used as insulators in MIM structures.
Innovation Solution
A thermal treatment process is applied to convert amorphous ZrO2 to cubic ZrO2 within a BEOL compatible temperature range, forming a TiN/cubic ZrO2/TiN stack, which significantly increases the dielectric constant to 29-31, exceeding the limitations of untreated HfO2 or ZrO2, thereby enhancing MIMCAP performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the dielectric constant of the insulator material is increased to achieve higher capacitance, then the capacitance of the MIMCAP increases, but the leakage current also increases
Solution Approach 1:
The patent applies parameter changes by transforming the insulator material from amorphous phase to cubic crystalline phase through thermal treatment. This phase transformation changes the physical and electrical parameters of the material, achieving a dielectric constant of 29-31 while maintaining low leakage current characteristics that are not achievable with conventional amorphous high-k materials.
Solution Approach 2:
The core invention utilizes phase transitions by heating the amorphous insulator material (such as ZrO2 or HfO2) to transform it into the cubic crystalline phase. This phase transition enables the material to achieve superior dielectric properties with both high capacitance and low leakage current, resolving the trade-off between these two parameters.
2Quantity of substance
If conventional amorphous high-k dielectric materials are used to increase capacitance, then the dielectric constant increases, but the thermal budget limitations of BEOL processes prevent further optimization
Solution Approach 1:
The patent applies preliminary action by performing the phase transformation of the insulator material to the cubic phase before forming the top electrode of the MIMCAP. This preliminary thermal treatment enables the material to achieve its optimal dielectric state early in the process, allowing subsequent BEOL-compatible processing to proceed at lower temperatures without compromising the dielectric properties.
Solution Approach 2:
The invention utilizes phase transitions to transform amorphous high-k dielectric materials into the cubic crystalline phase through controlled thermal treatment. This phase transition enables the material to achieve a dielectric constant of 29-31, overcoming the thermal budget limitations of BEOL processes by establishing the optimal dielectric state before subsequent low-temperature processing steps.
3Quantity of substance
If the dielectric constant is increased using materials like HfO2 and ZrO2, then capacitance increases, but the material limitations restrict achieving sufficient capacitance with acceptable leakage
Solution Approach 1:
The patent applies parameter changes by inducing a crystalline phase transformation in the insulator material from amorphous to cubic phase. This fundamental parameter change in the material's physical state enables simultaneous achievement of high dielectric constant (29-31) and low leakage current, overcoming the inherent material limitations of conventional amorphous high-k dielectrics.
Solution Approach 2:
The invention utilizes phase transitions of ZrO2 or HfO2 from amorphous to cubic crystalline phase to fundamentally change the material's electrical properties. This phase transition enables the material to simultaneously provide high capacitance and low leakage current, resolving the reliability issue associated with conventional high-k dielectric 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
This approach allows for increased capacitance with reduced leakage current, maintaining BEOL compatibility and improving noise mitigation in high-speed semiconductor devices.
Implementation Method 1
The insulator layer is thermally treated such that the amorphous dielectric material undergoes a cubic phase transition, thereby forming a cubic phase dielectric material
Data Source
AI summary
Embodiments of the present invention are directed to a back-end-of-line (BEOL) compatible metal-insulator-metal on-chip decoupling capacitor (MIMCAP). This BEOL compatible process includes a thermal treatment for inducing an amorphous-to-cubic phase change in the insulating layer of the MIM stack prior to forming the top electrode. In a non-limiting embodiment of the invention, a bottom electrode layer is formed, and an insulator layer is formed on a surface of the bottom electrode layer. The insulator layer can include an amorphous dielectric material. The insulator layer is thermally treated such that the amorphous dielectric material undergoes a cubic phase transition, thereby forming a cubic phase dielectric material. A top electrode layer is formed on a surface of the cubic phase dielectric material of the insulator layer.