权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Development of Low-Resistivity Contact Materials for Future ULSIs

为未来 ULSI 开发低电阻率接触材料

基本信息

批准号：
08505001
负责人：
YASUDA Yukio
金额：
$ 21.25万
依托单位：
Nagoya University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (A)
财政年份：
1996
资助国家：
日本
起止时间：
1996 至 1998
项目状态：
已结题

项目摘要

We have investigated the formation technology of ohmic contacts with very low resistivity for future ULSI devices, such as the control of Schottky barrier heights at metal/Si interfaces, the very-high impurity doping and the surface reaction control using hydrogen termination. The main results obtained by this study are as follows :(1) We have introduced a SiGe interlayer at the metal/Si interface in order to control the interfacial barrier height. In the case of Ti/SiGe/Si (1O0) , Ti_5Ge_3, C49-TiSi_2 and C54-Ti (Si_1-_yGe_y) _2 are produced at 580ﾟC, 700ﾟC and >750ﾟC by rapid thermal annealing for 30 sec. It is found that C54-Ti(Si_1-_yGe_y)_2 is a low resistivity phase as well as C54-TiSi_2. Furthermore, the bandgap narrowing and the lowering of Schottky barrier heights are observed for Ti/SiGe/Si (l0O) systems, since Ge-rich SiGe layers are formed as a result of solid-phase reaction at the metal/SiGe interface.(2) The contact formation process using H-termination treatments has been developed and it is confirmed to be able to form interfaces with good electrical characteristics. In the case of Ti/p-SiGe/p-Si (100) contacts, it can be found that the trap density is reduced and a nearly idealistic interface is formed by annealing for 30 sec using RTA processes. On the other hand, an increase in leakage current is observed by RTA for n-type samples.(3) The correlation between contact resistivities and B doping concentrations has been examined in order to clarify a maximum doping concentration at metal/Si interfaces. The doping concentration about 2x10^<20> cm^<-3> is realized, which is very close to the solid solubility of B atoms in Si, and the contact resistivity can be explained by the theoretical calculation including the effect of impurity band formation.

我们研究了未来ULSI器件极低电阻率欧姆接触的形成技术，如金属/硅界面肖特基势垒高度的控制，极高杂质掺杂的控制，以及利用氢端接控制表面反应等。主要研究结果如下：(1)为了控制界面势垒高度，我们在金属/硅界面引入了SiGe过渡层。在Ti/SiGe/Si(100)的情况下，在580ﾟC、700ﾟC和&GT；750ﾟC下快速热退火30秒，得到了Ti5Ge_3、C49-TiSi_2和C54-Ti(Si_1-yGe_y)_2。发现C54-Ti(Si_1-_yGe_y)_2和C54-TiSi_2都是低阻相。此外，由于在金属/SiGe界面上的固相反应形成了富Ge的SiGe层，在Ti/SiGe/Si(10O)系统中观察到了禁带变窄和肖特基势垒高度降低的现象。(2)发展了H端处理的接触形成工艺，并证实该工艺能够形成具有良好电性能的界面。在Ti/p-SiGe/p-Si(100)接触的情况下，采用RTA工艺进行30秒的退火处理后，陷阱密度降低，形成了接近理想的界面。另一方面，RTA观察到n型样品的漏电流增加。(3)为了明确金属/硅界面的最大掺杂浓度，研究了接触电阻率与B掺杂浓度之间的关系。实现了B原子在Si中的固溶度为2×10^&lt；20&gt；cm^&lt；-3&gt；，接触电阻率可以用考虑杂质带形成效应的理论计算来解释。