Table 1 Brief comparison of performance/design parameters of CBRAM technology as an RF switch and as a memory.
CBRAM technology application | RF switch | Memory |
|---|---|---|
Resistance requirements | Low resistance states (LRS) should be necessarily less than a few ohms (e.g. < 100 Ω) and high resistance states (HRS) states should be greater than few kΩ to ensure adequate RF transmission and isolation24 | LRS and HRS states require only a notable distinction. A few kΩ at LRS (This is at least 100 times greater than what is desired for an RF switch application) and a few MΩ at HRS states are well acceptable4 |
Cell size | Cell size (feature size) of the order of micrometres. This is a trade-off, principally among two factors (a) The off-state capacitance of the switch: larger the cross-section area of electrodes facing each other, larger the off-state capacitance—we try to keep this low (b) For an RF switch unlike the memory, a few hundreds of mA of current handling are desired, even though a pin-point study is not done in this work, a larger feature size is desired to enhance this performance and prevent any thermal breakdown. In the presented case, the approximate cross section area of the electrodes (facing each other in an overlap) is 100 μm × 300 μm, and the ion-conductor thickness is 600 nm In addition, in our studies, we try to manufacture the switch using ‘clean-room less’ technologies using instrumentation compatible with industrial mass production and this naturally contributes to a slightly larger feature size than in ‘clean-room’ based techniques6,24 | Cell size (feature size) of the order of nanometres. As an example the memory devices presented in Refs.4,23 have an electrode surface area of the order of < 5 μm2 and ion-conductor thickness of < 50 nm |
Repeatability | Repeatability of LRS states with a good precision and accuracy to low resistance values are critical. Here, tolerance of LRS is more critical, than for the HRS | Repeatability of LRS and HRS states with a good separation among each are critical. In memory application the specific values of LRS and HRS are not critical as long as they fall in a given tolerance range (which is well higher than for RF switch applications) |
Reliability | Reliability and repeatability as a single stand-alone switching device is very critical. It is not easy to bypass an RF path if a dedicated CBRAM switch goes faulty in a given RF switch topology | Reliability as a group/memory block is important. A faulty CBRAM cell could be bypassed in a group without much impact on the overall efficiency of the memory block |
Critical requirements | Linearity, power handling capability, and switching speed are critical | Read–write speed is critical |
