利用NiFeCr种子层提高AMR薄膜信噪比研究

Strongly suppressed 1/f noise and enhanced SNR in permalloy films using NiFeCr seeds layer

NiFeCr种子层可以明显降低NiFe薄膜的低频噪声,提高信噪比。制备态下NiFeCr为种子层的NiFe薄膜的低频噪声比以Ta打底的NiFe薄膜的低频噪声下降10倍,250℃下保温2h退火后以Ta打底的NiFe薄膜的低频噪声因扩散而明显上升,而NiFeCr为种子层的NiFe薄膜的低频噪声则有小幅下降。电镜分析表明NiFeCr种子层与NiFe层形成良好的晶格匹配关系,可以基本实现NiFe完全外延式的生长。

Permalloy films have very low 1/f noise and high SNR using NiFeCr seeds.1/f noise in NiFeCr/NiFe/Ta films is only 10 percent as that in Ta/NiFe/Ta films in deposited shape.1/f noise in Ta/NiFe/Ta films would be greatly improved after 250℃ 2h annealing because of the diffusion in Ta/NiFe interface.While 1/f noise in NiFeCr/NiFe/Ta films would only a little reduced after the same annealing procedure.The TEM result reveals that NiFe layer has good lattice match with NiFeCr seeds layer,and has less defects than that in Ta/NiFe/Ta films.