超薄氧化层制备及其可靠性研究

文章简述了超薄氧化层SiO2,的击穿机理,采用了恒定电流法表征超薄氧化层TDDB效应,并研究了清洗方法,氧化温度,氧化方式等工艺因素对超薄氧化层的可靠性影响.实验表明,在850℃、900℃等高温条件下,可通过干氧N/O分压的方法制备厚度4nm~5nm、均一性小于2.0%超薄氧化层;RCA清洗工艺过程中,APM中的NH3...

The Study of Preparation and Relibility of the Ultra-thin Oxide

In this paper,the principle of ultra thin oxides＇ reakdown was simply introduced,the TDDB effect of ultra thin oxide was tested by the constant electric current.Meanwhile,the processing factors which influence the relibility of ultra thin oxide,such as the methods of washing、the temperature of oxidation,the methods of oxidation and so on,were studied.The results shown that the 4nm～5nm oxide with less than 2.0% uniformity are prepared by N/O Dry oxidation in the temperature of 850℃ and 900℃;In the process of RCA washing,excessively high content of NH3.H2O in the APM cause the damage and roughness of silicon surface,and then result in initial-invalidation and lowness QBD of ultra thin oxide;In the process of N/O Dry oxidation,N2 anneal can effectively improve the densify and QBD of ultra thin oxide.The 5nm oxide with excellent reliability,which including maximize breakdown voltage 49.1V,averagen breakdown voltage 7.1V,breakdown electric field 16.62 MV.cm-1,the ratio of initial-invalidation 3.85%,and 61.54% points with QBD15C.cm-2,was successfully prepared.