Si/Sb superlattice-like thin films for ultrafast and low power phase change memory application

Abstract

After compositing with Si, the superlattice-like (SLL) Si/Sb thin film had higher crystallization temperature (~231 o C), larger crystallization activation energy (2.95 eV), and better data retention ability (126 o C for 10 years). The crystallization of Sb in SLL Si/Sb thin films was restrained by the multilayer interfaces. The reversible resistance transition could be achieved by an electric pulse as short as 10 ns for [Si(22nm)/Sb(2nm)] 2-based PCM cell. A lower operation power consumption of 0.02 mW and a good endurance of 1.0×10 5 cycles was achieved. In addition, SLL [Si(22nm)/Sb(2nm)] 2 thin film showed a low thermal conductivity of 0.11 W/(m•K).

Improvement of the thermal stability of Sb thin film through erbium doping

“…20 Thus, the increase in E a indicates poor atomic mobility as a result of Er addition. These results are also consistent with Si doped Sb, 13 Al doped Sb 2 Te 3 17 and Cr doped Sb 3 Te 1 . 24 Furthermore, the 10 year lifetime for Er doped Sb films increases from 22 °C for Er 0.002 Sb 0.998 to 145 °C for Er 0.018 Sb 0.982 .…”

“…Tominaga et al 12 have mentioned that a sputtered Sb thin film with a thickness of more than 10 nm is usually in the crystalline state and other researchers also have had similar results. 13 It is well known that doping is one of the effective ways to improve phase change properties. 14 Recently, phase change materials, with N doping, 15,16 Al doping, 17 Ti doping, 18 etc., have been extensively studied.…”

High Reliability and Fast‐Speed Phase‐Change Memory Based on Sb70Se30/SiO2 Multilayer Thin Films

“…With the increase of SiO thickness, E g of amorphous lms spreads more widely. In general, the carrier density inside the semiconductors is proportional to exp(−E a /2KT) [23], and the increase of the bandgap will result in the reduction of carriers, which makes a major contribution to the increase of lm resistivity. us, the activation energy for crystallization is increased, improving the stability of the amorphous phase.…”

“…Flash is now the mainstream of the nonvolatile memory market, but flash has several drawbacks such as its long operation time, the high voltage required for writing operations, and the fact used to store charges cannot meet the law of proportional reduction when it is very small [2][3][4]. Phasechange memory due to read and write with fast speed, highdensity storage capacity, and compatible with complementary metal-oxide-semiconductor (CMOS), which regarded as the most promising alternative flash memory, becomes the mainstream of the next generation of nonvolatile storage technology [5,6]. In order to solve the problems of large operation current and thermal interference, the whole development trend of PCM is in the three-dimensional direction to the nanometer scale.…”

Superlattice‐like Zn 15 Sb 85 /Ga 30 Sb 70 thin films for low power and ultrafast phase change memory application

“…The most widely used phase change materials are chalcogenide, of which Ge 2 Sb 2 Te 5 (GST) has been extensively studied and widely used in commercial DVD‐RAM for a long time with its excellent performance [7]. However, some aspects limit its application in PCM, such as the low activation energy (2.24 eV for the phase change from the crystal to rock salt structure) [8, 9], the great density change (6.8% from amorphous to NaCl‐type crystal state) [10], high RESET current (>1 mA) [11] and the long crystallisation time (∼100 ns) [11]. It is reported that Sb‐rich phase change material has fast switching speed due to its growth‐dominated crystallisation mechanism, such as Ge–Sb [12], Sn–Sb [13] and Cu–Sb–Te [14].…”