Amorphous Oxide Film Threshold Voltage Stability
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Solution Overview
Problem
The TANOS structure in flash memory semiconductor devices has low reliability due to changes in threshold voltage, affecting data writing and deletion operations.
Innovation Solution
A method of manufacturing semiconductor devices involves forming an amorphous first oxide film with aluminum, yttrium, or lanthanum, and modifying it to include a second element like hafnium, maintaining a lower concentration of the second element to prevent crystallization and threshold voltage changes, even at high temperatures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional oxide film structure is used in flash memory, then the device can be manufactured with standard processes, but the threshold voltage changes and reliability is low
Solution Approach 1:
The patent applies composite materials by creating a multi-layer oxide film structure consisting of a first oxide film (Al2O3, Y2O3, or La2O3) and a second oxide film (HfO2, ZrO2, TiO2, Nb2O5, Ta2O5, SrO, or SiO2). This composite structure combines the beneficial properties of different oxides to achieve stable threshold voltage while maintaining manufacturability through established semiconductor fabrication processes
Solution Approach 2:
The patent implements local quality by doping the second oxide film with specific elements (Al, Y, or La) at controlled concentrations (0.1-10 at%). This localized modification of composition within the oxide film structure enables precise control of electrical properties and threshold voltage stability without affecting the entire device structure
2Reliability
If the oxide film is doped with higher concentration of second element to prevent crystallization, then threshold voltage stability improves, but the film may become too complex to manufacture
Solution Approach 1:
The patent applies parameter changes by precisely controlling the concentration of the second element in the oxide film within the range of 0.1-10 at%. This parameter optimization prevents crystallization and ensures threshold voltage stability while keeping the manufacturing process within achievable precision limits for standard semiconductor fabrication equipment
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 ensures the semiconductor device's threshold voltage remains stable, enhancing the reliability of charge-trap type flash memory operations by maintaining the amorphous state of the Hf-doped Al2O3 film during thermal treatment.
Implementation Method 1
forming an amorphous first oxide film including a first element on a substrate
Implementation Method 2
modifying the first oxide film to an amorphous second oxide film including the first element and a second element different from the first element by adding the second element to the first oxide film
Data Source
AI summary
Provided are a semiconductor device manufacturing method by which a semiconductor device in which a threshold voltage is suppressed from changing can be manufactured, a substrate processing method and apparatus, a non-transitory computer-readable recording medium, and the semiconductor device. The semiconductor device manufacturing method includes forming an amorphous first oxide film including a first element on a substrate, and modifying the first oxide film to an amorphous second oxide film including the first element and a second element different from the first element by adding the second element to the first oxide film. The first element includes at least one element selected from a group consisting of aluminum, yttrium and lanthanum. A concentration of the second element in the second oxide film is controlled to be lower than that of the first element in the second oxide film.