硅离子注入对Ge2Sb2Te5结构和电阻的影响

采用磁控射频溅射法制备了Ge2Sb2Te5薄膜，利用离子注入法研究了硅掺杂对薄膜结构和电阻性能的影响. 研究发现，由于硅的掺杂，Ge2Sb2Te5薄膜的结构不仅保留了原有的面心立方低温晶相和六方高温晶相，而且出现了菱形六面体的Sb2Te3晶相；掺杂硅后，Ge2Sb2Te5薄膜的电阻有较大变化，晶态电阻的提高有利于降低非晶化相变过程的操作电流，薄膜电阻-温度稳定性的改善可保证有较宽的操作电流波动范围.     

硅离子注入对Ge2Sb2Te5结构和电阻的影响

采用磁控射频溅射法制备了Ge2Sb2Te5薄膜,利用离子注入法研究了硅掺杂对薄膜结构和电阻性能的影响.研究发现,由于硅的掺杂,Ge2Sb2Te5薄膜的结构不仅保留了原有的面心立方低温晶相和六方高温晶相,而且出现了菱形六面体的Sb2Te3晶相;掺杂硅后,Ge2Sb2Te5薄膜的电阻有较大变化,晶态电阻的提高有利于降低非晶化相变过程的操作电流,薄膜电阻-温度稳定性的改善可保证有较宽的操作电流波动范围.     

硫系相变材料Ge1Sb2Te4和Ge2Sb2Te5薄膜相变速度及电学输运性质研究

利用磁控溅射方法制备了Ge1Sb2Te4和Ge2Sb2Te5两种相变存贮材料的薄膜.原位X射线衍射(XRD)的结果表明,随着退火温度的升高,Ge1Sb2Te4和Ge2Sb2Te5薄膜都逐步晶化,材料结构发生了从非晶态到面心立方结构、再到六角密堆结构的转变.由衍射峰的半宽高可以看出,在达到第一次相变温度后,Ge2Sb2T...     

溅射参数对Ge2Sb2Te5薄膜光学常数的影响

研究了溅射参数对Ge2Sb2Te5薄膜的光学常数随波长变化关系的影响,结果表明：(1)当溅射功率一定时,随溅射氩气气压的增加Ge2Sb2Te5薄膜的折射率先增大后减小,而消光系数先减小后增大.(2)当溅射氩气气压一定时,对于非晶态薄膜样品,在500nm波长以下,折射率随溅射功率的增加先增加后减小,消光系数则逐渐减小;在500nm以上,折射率随溅射功率的增加逐渐减少,消光系数先减小后增加.对于晶态薄膜样品,在整个波长范围折射率随溅射功率的增加先减小后增加,消光系数则逐渐减少.(3)薄膜样品的光学常数都随波长的变化而变化,在长波长范围变化较大,短波长范围变化较小.探讨了影响Ge2Sb2Te5薄膜光学常数的机理.     

制备条件对Ge2Sb2Te5薄膜电学性能的影响

研究了磁控溅射制备Ge2Sb2Te5薄膜时，制备条件诸如功率、气压等对薄膜性能的影响. 主要通过测量薄膜方块电阻随退火温度的变化情况，探索Ge2Sb2Te5薄膜的成长机理. 实验结果表明，不同溅射功率下制备的薄膜经不同温度退火后方块电阻没有明显的区别，而随着溅射气压的上升，薄膜方块电阻随退火温度的增加，下降的速率增加，意味着由面心立方结构转变为六方结构所需的结晶温度降低     

制备条件对Ge2Sb2Te5薄膜电学性能的影响

研究了磁控溅射制备Ge2Sb2Te5薄膜时,制备条件诸如功率、气压等对薄膜性能的影响.主要通过测量薄膜方块电阻随退火温度的变化情况,探索Ge2Sb2Te5薄膜的成长机理.实验结果表明,不同溅射功率下制备的薄膜经不同温度退火后方块电阻没有明显的区别,而随着溅射气压的上升,薄膜方块电阻随退火温度的增加,下降的速率增加,意味着由面心立方结构转变为六方结构所需的结晶温度降低.     

制备条件对Ge2Sb2Te5薄膜电学性能的影响

研究了磁控溅射制备Ge2Sb2Te5薄膜时,制备条件诸如功率、气压等对薄膜性能的影响.主要通过测量薄膜方块电阻随退火温度的变化情况,探索Ge2Sb2Te5薄膜的成长机理.实验结果表明,不同溅射功率下制备的薄膜经不同温度退火后方块电阻没有明显的区别,而随着溅射气压的上升,薄膜方块电阻随退火温度的增加,下降的速率增加,意味着由面心立方结构转变为六方结构所需的结晶温度降低.     

激光致晶态Ge2Sb2Te5相变介质的光学常数

利用椭偏仪和光谱仪研究了结晶程度对Ge2Sb2Te5相变薄膜光学常数的影响.当初始化仪转速固定时,随激光功率的增加,折射率基本随之减小,消光系数逐渐增大,透过率逐渐减小;当激光功率固定时,随转速的增大,折射率也随之增大,消光系数随之减小,透过率逐渐增加.非晶态与晶态间的变换、薄膜微结构的变化(包括原子间键合状态的变化)以及薄膜内残余应力是影响Ge2Sb2Te5相变薄膜复数折射率的主要原因.测量了CD-RW(可擦重写光盘)中Ge2Sb2Te5薄膜非晶态和晶态的反射率.     

激光致晶态Ge2Sb2Te5相变介质的光学常数

利用椭偏仪和光谱仪研究了结晶程度对Ge2Sb2Te5相变薄膜光学常数的影响.当初始化仪转速固定时,随激光功率的增加,折射率基本随之减小,消光系数逐渐增大,透过率逐渐减小;当激光功率固定时,随转速的增大,折射率也随之增大,消光系数随之减小,透过率逐渐增加.非晶态与晶态间的变换、薄膜微结构的变化(包括原子间键合状态的变化)以及薄膜内残余应力是影响Ge2Sb2Te5相变薄膜复数折射率的主要原因.测量了CD-RW(可擦重写光盘)中Ge2Sb2Te5薄膜非晶态和晶态的反射率.     

钛掺杂对Ge2Sb2Te5薄膜相变特性的改善

利用椭偏光谱术与XRD对钛掺杂Ge2Sb2Te5薄膜中钛元素对体系的光学性质及其微结构的影响进行了实验研究。进而对该薄膜进行的变温阻抗实验表明,钛掺杂Ge2Sb2Te5薄膜与未掺杂的薄膜相比具有更好的热稳定性。基于对薄膜样品的数据保持能力测试的实验数据,经阿伦纽斯外推处理可知,钛掺杂Ge2Sb2Te5薄膜样品的10年数据保持温度要高于未掺杂Ge2Sb2Te5薄膜样品。本文的实验结果均证实,钛掺杂Ge2Sb2Te5薄膜更适合应用于相变随机存取存储器中。     

The Effect of Synthesis and Heat Treatment Modes on the Local Structure of a Ge2Sb2Te5 Chalcogenide Semiconductor

Semiconductors - Features of amorphous state?crystal phase transitions have been studied by X-ray diffractometry and Raman spectroscopy in their dependence on methods for obtaining...     

Multilevel Recording in Ge2Sb2Te5 Thin Films

Semiconductors - The current–voltage characteristics measured on Ge2Sb2Te5 thin films in the current mode are studied. The effect of multilevel recording is established when applying...     

Electrode Materials for Ge2Sb2Te5-Based Memristors

The memristive characteristics of Ge₂Sb₂Te₅ (GST) as a representative chalcogenide material have been verified and show great potential for memory applications. This paper focuses on the influence of different electrode materials on the properties of GST-based memristors. Several electrode materials (Ti₃W₇, Ag, Cu, and Ta) were adopted in devices with a top electrode (TE)/GST/bottom electrode (BE) layer structure. Through different current–voltage (I–V) curves, it was demonstrated that devices with Ag or Cu electrodes are suitable for GST-based memristors, while those utilizing inert electrodes are not. Because of their relatively smaller radius and lower binding energy, it is much easier for Ag and Cu to diffuse into the GST layer and form conductive filaments. The results obtained from memristors annealed at different temperatures further support the conductive filament model. Moreover, an optimized Cu/Ag/GST/Cu device structure different from the traditional TE/GST/BE structure is proposed, showing improved stability with higher R _off/R _on ratio and good endurance.     

Tunable Volatility of Ge2Sb2Te5 in Integrated Photonics

The operation of a single class of optical materials in both a volatile and nonvolatile manner is becoming increasingly important in many applications. This is particularly true in the newly emerging field of photonic neuromorphic computing, where it is desirable to have both volatile (short‐term transient) and nonvolatile (long‐term static) memory operation, for instance, to mimic the behavior of biological neurons and synapses. The search for such materials thus far have focused on phase change materials where typically two different types are required for the two different operational regimes. In this paper, a tunable volatile/nonvolatile response is demonstrated in a photonic phase‐change memory cell based on the commonly employed nonvolatile material Ge₂Sb₂Te₅ (GST). A time‐dependent, multiphysics simulation framework is developed to corroborate the experimental results, allowing us to spatially resolve the recrystallization dynamics within the memory cell. It is then demonstrated that this unique approach to photonic memory enables both data storage with tunable volatility and detection of coincident events between two pulse trains on an integrated chip. Finally, improved efficiency and all‐optical routing with controlled volatility are demonstrated in a ring resonator. These crucial results show that volatility is intrinsically tunable in normally nonvolatile GST which can be used in both regimes interchangeably.     

初始化条件对Ge2Sb2Te5相变光盘反射率和载噪比的影响

Ge2 Sb2 Te5相变光盘的反射率对比度和载噪比受初始化条件影响很大。研究表明 ,反射率对比度在转速比较低时随功率增加而增大 ,而转速较高时随功率增加而减小 ;反射率对比度基本随转速增加而减小 ,不同波长处的反射率对比度相差比较大 ;载噪比随初始化功率和转速的增加都是先增大后减小 ;最佳初始化条件为 :功率为 110 0～ 130 0mW ,转速为 3 0～ 4 2m s。     

Local Structure and Anti-Structural Defects of Tin in Amorphous and Crystalline Ge2Sb2Te5 Films

Semiconductors - The absorption Mössbauer spectroscopy on 119Sn impurity centers shows that germanium atoms in the structure of amorphous and polycrystalline Ge2Sb2Te5 films have different...