Conventional semiconductor technologies have nearly reached their physical limits and it is necessary to look for replacements. It is important that these new materials and principles allow for a high density of functional memory units at the lowest energy intensity of their use. One of the major candidates for new types of memory is resistive switching based on the creation of a reformable conductive pathway between electrodes separated by the ionic conductor, i.e. Electrochemical Metallization (ECM) cell.
Conventional ECM device comprises of an inert electrode (e.g. Al, Pt or W), an active electrode (e.g. Ag or Cu) and a metal doped electrolyte (e.g. Ag or Cu doped chalcogenide compounds or certain oxides). However, the active electrode is vulnerable to thermal or photo degradation; the Ag or Cu element would continuously dissolve into the electrolyte, causing the detachment between the active electrode and electrolyte. Moreover, the continuous dissolution of Ag or Cu from active electrode increases the concentration of Ag or Cu dopants in the electrolyte. These cause device failures and limit the development of conventional ECM based Resistive Random Access Memory (RRAM) device.
A novel ECM based RRAM device that is able to avoid excessive dissolution of active electrode into the electrolyte, and is also highly resistant to thermal and photo degradation is described herein. Besides the stability to memory switching (>107 cycles), the novel ECM RRAM device has fast operational speed.
Technology Features, Specifications and Advantages
The described technology composes of:
- An ECM based RRAM device that can be fabricated with both inert electrodes and a combination of cells in a single device to increase its unique properties
- Specific mode of the proposed solution that ensures the improved properties of the device by avoiding excessive dissolution of the active electrode into the electrolyte
- A device with write voltage of 1/3 V and read voltage of up to 0.5 V.
As the device exhibits thermal and radiation stability on top of excellent RRAM properties, it can be used in:
- Space and nuclear applications where the effect of radiation has long been a concern
- Medical community with the proliferation of implantable devices (which are gamma radiation sterilized prior to use) and the increased use of radiation for disease diagnostics and treatment
- Electronics operating in harsh environments
- Device that exhibits thermal stability up to at least 100°C and thanks to its material composition and construction, is also resistant to cosmic radiation
- An ECM based RRAM device that possesses superb properties such as:
- Good scalability (<20 nm)
- Low operational current (< 1 µA)
- Large High-Low resistivity (> 10)
- Fast operational speed (< 10 ns)
- Good endurance (> 107 cycles)
- Long retention (> 10 years)