Limits...
Impact of device size and thickness of Al2O 3 film on the Cu pillar and resistive switching characteristics for 3D cross-point memory application.

Panja R, Roy S, Jana D, Maikap S - Nanoscale Res Lett (2014)

Bottom Line: The 8-μm devices show 100% yield of Cu pillars, whereas only 74% successful is observed for the 0.4-μm devices, because smaller size devices have higher Joule heating effect and larger size devices show long read endurance of 10(5) cycles at a high read voltage of -1.5 V.On the other hand, the resistive switching memory characteristics of the 0.4-μm devices with a 2-nm-thick Al2O3 film show superior as compared to those of both the larger device sizes and thicker (10 nm) Al2O3 film, owing to higher Cu diffusion rate for the larger size and thicker Al2O3 film.This conductive bridging resistive random access memory (CBRAM) device is forming free at a current compliance (CC) of 30 μA (even at a lowest CC of 0.1 μA) and operation voltage of ±3 V at a high resistance ratio of >10(4).

View Article: PubMed Central - PubMed

Affiliation: Thin Film Nano Tech. Lab., Department of Electronic Engineering, Chang Gung University, 259 Wen-Hwa 1st Rd., Kwei-Shan, Tao-Yuan, 333, Taiwan, panjarajeswar@gmail.com.

ABSTRACT
Impact of the device size and thickness of Al2O3 film on the Cu pillars and resistive switching memory characteristics of the Al/Cu/Al2O3/TiN structures have been investigated for the first time. The memory device size and thickness of Al2O3 of 18 nm are observed by transmission electron microscope image. The 20-nm-thick Al2O3 films have been used for the Cu pillar formation (i.e., stronger Cu filaments) in the Al/Cu/Al2O3/TiN structures, which can be used for three-dimensional (3D) cross-point architecture as reported previously Nanoscale Res. Lett.9:366, 2014. Fifty randomly picked devices with sizes ranging from 8 × 8 to 0.4 × 0.4 μm(2) have been measured. The 8-μm devices show 100% yield of Cu pillars, whereas only 74% successful is observed for the 0.4-μm devices, because smaller size devices have higher Joule heating effect and larger size devices show long read endurance of 10(5) cycles at a high read voltage of -1.5 V. On the other hand, the resistive switching memory characteristics of the 0.4-μm devices with a 2-nm-thick Al2O3 film show superior as compared to those of both the larger device sizes and thicker (10 nm) Al2O3 film, owing to higher Cu diffusion rate for the larger size and thicker Al2O3 film. In consequence, higher device-to-device uniformity of 88% and lower average RESET current of approximately 328 μA are observed for the 0.4-μm devices with a 2-nm-thick Al2O3 film. Data retention capability of our memory device of >48 h makes it a promising one for future nanoscale nonvolatile application. This conductive bridging resistive random access memory (CBRAM) device is forming free at a current compliance (CC) of 30 μA (even at a lowest CC of 0.1 μA) and operation voltage of ±3 V at a high resistance ratio of >10(4).

No MeSH data available.


Related in: MedlinePlus

TEM images of an Al/Cu/Al2O3/TiN structure. (a) TEM image shows the device size of 0.5 × 0.5 μm2. (b) HRTEM image shows Cu/Al2O3/TiN structure. The thickness of insulating layer is approximately 18 nm.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4494016&req=5

Fig1: TEM images of an Al/Cu/Al2O3/TiN structure. (a) TEM image shows the device size of 0.5 × 0.5 μm2. (b) HRTEM image shows Cu/Al2O3/TiN structure. The thickness of insulating layer is approximately 18 nm.

Mentions: Figure 1a shows TEM image of an Al/Cu/Al2O3/TiN via-hole device. All layers are observed clearly. The device size of approximately 0.5 × 0.5 μm2 is observed. Figure 1b shows high-resolution TEM image inside the via-hole region. The thickness of Al2O3 layer is approximately 18 nm, including a thin TiOxNy layer on the TiN surface. This Al2O3 film shows amorphous. Due to the thicker Al2O3 film, the stronger Cu filament (or pillar) could be formed inside the via-hole region for 3D cross-point memory application, which has been discussed below.Figure 1


Impact of device size and thickness of Al2O 3 film on the Cu pillar and resistive switching characteristics for 3D cross-point memory application.

Panja R, Roy S, Jana D, Maikap S - Nanoscale Res Lett (2014)

TEM images of an Al/Cu/Al2O3/TiN structure. (a) TEM image shows the device size of 0.5 × 0.5 μm2. (b) HRTEM image shows Cu/Al2O3/TiN structure. The thickness of insulating layer is approximately 18 nm.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4494016&req=5

Fig1: TEM images of an Al/Cu/Al2O3/TiN structure. (a) TEM image shows the device size of 0.5 × 0.5 μm2. (b) HRTEM image shows Cu/Al2O3/TiN structure. The thickness of insulating layer is approximately 18 nm.
Mentions: Figure 1a shows TEM image of an Al/Cu/Al2O3/TiN via-hole device. All layers are observed clearly. The device size of approximately 0.5 × 0.5 μm2 is observed. Figure 1b shows high-resolution TEM image inside the via-hole region. The thickness of Al2O3 layer is approximately 18 nm, including a thin TiOxNy layer on the TiN surface. This Al2O3 film shows amorphous. Due to the thicker Al2O3 film, the stronger Cu filament (or pillar) could be formed inside the via-hole region for 3D cross-point memory application, which has been discussed below.Figure 1

Bottom Line: The 8-μm devices show 100% yield of Cu pillars, whereas only 74% successful is observed for the 0.4-μm devices, because smaller size devices have higher Joule heating effect and larger size devices show long read endurance of 10(5) cycles at a high read voltage of -1.5 V.On the other hand, the resistive switching memory characteristics of the 0.4-μm devices with a 2-nm-thick Al2O3 film show superior as compared to those of both the larger device sizes and thicker (10 nm) Al2O3 film, owing to higher Cu diffusion rate for the larger size and thicker Al2O3 film.This conductive bridging resistive random access memory (CBRAM) device is forming free at a current compliance (CC) of 30 μA (even at a lowest CC of 0.1 μA) and operation voltage of ±3 V at a high resistance ratio of >10(4).

View Article: PubMed Central - PubMed

Affiliation: Thin Film Nano Tech. Lab., Department of Electronic Engineering, Chang Gung University, 259 Wen-Hwa 1st Rd., Kwei-Shan, Tao-Yuan, 333, Taiwan, panjarajeswar@gmail.com.

ABSTRACT
Impact of the device size and thickness of Al2O3 film on the Cu pillars and resistive switching memory characteristics of the Al/Cu/Al2O3/TiN structures have been investigated for the first time. The memory device size and thickness of Al2O3 of 18 nm are observed by transmission electron microscope image. The 20-nm-thick Al2O3 films have been used for the Cu pillar formation (i.e., stronger Cu filaments) in the Al/Cu/Al2O3/TiN structures, which can be used for three-dimensional (3D) cross-point architecture as reported previously Nanoscale Res. Lett.9:366, 2014. Fifty randomly picked devices with sizes ranging from 8 × 8 to 0.4 × 0.4 μm(2) have been measured. The 8-μm devices show 100% yield of Cu pillars, whereas only 74% successful is observed for the 0.4-μm devices, because smaller size devices have higher Joule heating effect and larger size devices show long read endurance of 10(5) cycles at a high read voltage of -1.5 V. On the other hand, the resistive switching memory characteristics of the 0.4-μm devices with a 2-nm-thick Al2O3 film show superior as compared to those of both the larger device sizes and thicker (10 nm) Al2O3 film, owing to higher Cu diffusion rate for the larger size and thicker Al2O3 film. In consequence, higher device-to-device uniformity of 88% and lower average RESET current of approximately 328 μA are observed for the 0.4-μm devices with a 2-nm-thick Al2O3 film. Data retention capability of our memory device of >48 h makes it a promising one for future nanoscale nonvolatile application. This conductive bridging resistive random access memory (CBRAM) device is forming free at a current compliance (CC) of 30 μA (even at a lowest CC of 0.1 μA) and operation voltage of ±3 V at a high resistance ratio of >10(4).

No MeSH data available.


Related in: MedlinePlus