多晶硅薄膜和金属铝接触的研究

Research on Poly-Si/Al Contact

研究了ｎ型多晶硅薄膜和铝的欧姆按触、整流接触。在掺杂浓度Ｎ≥２．９×１０１９ ｃｍ－３的情况下为欧姆接触：在掺杂浓度Ｎ≤２．９×１０１８ｃｍ－３的情况下为整流接触； 用ＴＬＭ方法测出了Ｎ＝２．９×１０１９ｃｍ－３时的接触电阻率ρｃ＝５．５４×１０－３Ω．ｃｍ２； 从理论上定量地分析了掺杂浓度（１．４×１０１７～２．９×１０１９）ｃｍ－３的Ｕ－Ｉ特性曲线．理 论计算结果和实验数据符合较好．讨论了肖特基势垒高度φｂ和晶粒间界势垒高度φｇ 随掺杂浓度变化的规律，φｂ不随Ｎ变化，保持为常数；而φｇ却有极值。在实验 方面．探讨了用Ｔｉ代替Ａ１实现低阻浅结欧姆接触的可能性。在掺杂浓度较低的情 况下，给出了制备欧姆接触的方法。

N-type Poly-Si/Al oh mic and rectified contacts have been investigated for (N=2.9 ×1018cm-3) and (N≤2.9×1018cm-3) doping respectively.Using TLM method, the contact resistivity (ρc=5.54 ×10-3 Ω· cm2) is obtained from the measurement of (2.9 × 1019cm-3) doping sample. At Al sintering tempera-ture<4500C, the contact resistivity of n-type Poly-Si/silicide/Al is two orders lower than that of Poly-Si/A1 at (2.0×1019cm-3) doping. U-I characteristics with doping concentration (1.4×1017~2.9×1019)cm-3 have been analyzed quantitatively. A way to form oh mic contact of n-type Poly-Si/Al with light doping concentration is proposed. By comparing theoretical and experimental results, it is found that Schottkg barrier height φb is independent of doping concentration and grain boundary barrier height φg varying with doping concentration has a maximum.