Doped Oxide Capacitor Structure for High-Aspect Memory Cells
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
As semiconductor memory devices become increasingly integrated, the aspect ratio of circuit patterns increases, leading to higher process difficulties and defects such as pattern collapse, which complicates the fabrication of capacitors with improved capacitance and reduced stress.
Innovation Solution
A capacitor structure is developed with a lower electrode comprising a metal oxide film and a doping oxide film doped with impurity elements like silicon, aluminum, or hafnium, which includes Group 5 to Group 11 or Group 15 metal elements, interposed between the electrode film and the capacitor dielectric film to enhance capacitance and reduce stress.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the aspect ratio of circuit patterns is increased to implement more semiconductor memory devices in the same area, then the integration density is improved, but the process difficulty increases and defects such as pattern collapse occur
Solution Approach 1:
The patent introduces a doping oxide film with specific doping concentrations (0.01-5 atomic% of metal element, 0.1-5 atomic% of impurity element) to modify the physical and chemical properties of the lower electrode structure, thereby reducing stress and preventing pattern collapse while maintaining high aspect ratios for improved integration density
Solution Approach 2:
The lower electrode is constructed as a composite structure with multiple layers including electrode film, metal oxide film, and doping oxide film with different material compositions. This composite structure optimizes both mechanical strength to prevent collapse and electrical properties for capacitor function, enabling high integration density
2Reliability
If a doping oxide film is introduced to improve capacitance and reduce stress, then the dielectric constant is enhanced and stress is reduced, but the device structure becomes more complex
Solution Approach 1:
The doping oxide film is selectively positioned only in the lower electrode region where stress management and capacitance enhancement are most critical, rather than throughout the entire capacitor structure. This localized approach improves reliability while minimizing overall device complexity
Solution Approach 2:
The doping oxide film acts as an intermediary layer between the electrode film and metal oxide film, providing stress relief and enhancing dielectric properties without requiring fundamental redesign of the entire capacitor structure, thus balancing reliability improvement with acceptable 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 proposed structure achieves improved capacitance and reduced stress in capacitors by minimizing the formation of depletion regions and preventing excessive oxidation of the metal oxide film, thereby enhancing the dielectric constant and reducing fabrication challenges.
Implementation Method 1
the lower electrode includes a doping oxide film including an oxide of the first metal element doped with a second metal element
Implementation Method 2
preventing excessive oxidation of the metal oxide film
Data Source
AI summary
A capacitor structure, a semiconductor memory device including the same, a method for fabricating the same, and a method for fabricating a semiconductor device including the same are provided. The capacitor structure includes a lower electrode, an upper electrode, and a capacitor dielectric film which is interposed between the lower electrode and the upper electrode, wherein the lower electrode includes an electrode film including a first metal element, and a doping oxide film including an oxide of the first metal element between the electrode film and the capacitor dielectric film, and the doping oxide film further includes a second metal element including at least one of Group 5 to Group 11 and Group 15 metal elements, and an impurity element including at least one of silicon (Si), aluminum (Al), zirconium (Zr) and hafnium (Hf).