Chinese Academy of Sciences

Liangcai Wu

Zhitang Song

Min Zhu

Cheng Peng

Feng Rao

Songlin Feng

Xilin Zhou

Bo Tong Liu

Kun Ren

An Sb&#x2014;Te&#x2014;Ti phase-change thin-film material applicable to a phase-change memory and preparation thereof. The Sb&#x2014;Te&#x2014;Ti phase-change memory material is formed by doping an Sb&#x2014;Te phase-change material with Ti, Ti forms bonds with both Sb and Te, and the Sb&#x2014;Te&#x2014;Ti phase-change memory material has a chemical formula SbTeTi, where 0&#x3c;x&#x3c;80 and 0&#x3c;y&#x3c;100&#x2212;x. When the Sb&#x2014;Te&#x2014;Ti phase-change memory material is a Ti&#x2014;SbTephase-change memory material, Ti atoms replace Sb atoms, and phase separation does not occur. The crystallization temperature of the Sb&#x2014;Te&#x2014;Ti phase-change memory material is significantly risen, retention is improved, and thermal stability is enhanced; meanwhile, the amorphous state resistance decreases, and the crystalline state resistance increases; and the Sb&#x2014;Te&#x2014;Ti phase-change memory material has wide application in phase-change memories.

Sb&#x2014;Te&#x2014;Ti phase-change memory material and Ti&#x2014;Sb2Te3 phase-change memory material

The present invention discloses an Al&#x2014;Sb&#x2014;Te phase change material used for PCM and fabrication method thereof. Said phase change material, which can be prepared by PVD, CVD, ALD, PLD, EBE, and ED, is a mixture of three elements aluminum (Al), antimony (Sb) and tellurium (Te) with a general formula of Al(SbTe), where 0&#x3c;x&#x2266;0.85, 0.67&#x2266;y&#x2266;7. Said material is electrically driven from outside. By adjusting the content of three elements in the mixture, storage materials with different crystallization temperatures, melting temperatures and activation energies of crystallization can be achieved. Any two elements of aluminum, antimony and tellurium can be bonded to each other, so the adjustability is very high, maintaining the phase change properties in a wide range. Compared with conventional GeSbTe, the materials achieved by properly adjusting the element ratio in Al(SbTe)have higher crystallization temperatures, better thermal stability and data retention, and lower melting temperatures, while at the same time inheriting the fast phase change capability from SbTe. Moreover, as a common element used in microelectronics, aluminum (Al) features mature technology and nice compatibility with CMOS.

Al-Sb-Te phase change material used for phase change memory and fabrication method thereof

The present invention discloses a phase change memory structure having low-k dielectric heat-insulating material and fabrication method thereof, wherein the phase change memory cell comprises diode, heating electrode, reversible phase change resistor, top electrode and etc; the heating electrode and reversible phase change resistor are surrounded by low-k dielectric heat-insulating layer; an anti-diffusion dielectric layer is designed between the reversible phase change resistor and the low-k dielectric heat-insulating layer surrounding thereof. The present invention utilizes low-k dielectric material as heat-insulating material, thereby avoiding thermal crosstalk and mutual influence during operation between phase change memory cells, enhancing the reliability of devices, and eliminating the influence of temperature, pressure and etc. on phase change random access memory (PCRAM) data retention during the change from amorphous to polycrystalline states. Furthermore, an anti-diffusion dielectric layer is prepared between the low-k dielectric material and the phase change material, which can be used to prevent the elements of the phase change material from diffusing to low-k dielectric material. The fabrication process of said phase change memory is compatible with standard complementary metal-oxide semiconductor (CMOS) process and the chemical mechanical polishing (CMP) process with low pressure and light corrosion is adopted in polishing.

Phase change memory structure having low-K dielectric heat-insulating material and fabrication method thereof

Growing community of inventors

Shanghai, China

Liangcai Wu