Saw K G, Esa S R
School of Distance Education, Universiti Sains Malaysia, 11800, Penang, Malaysia.
MIMOS Semiconductor (M) Sdn Bhd, Technology Park Malaysia, 57000, Kuala Lumpur, Malaysia.
Sci Rep. 2021 Apr 7;11(1):7644. doi: 10.1038/s41598-021-87386-6.
Time-of-flight secondary ion mass spectrometry fragment analysis remains a challenging task. The fragment appearance regularity (FAR) rule is particularly useful for two-element compounds such as ZnO. Ion fragments appearing in the form of ZnO obey the rule [Formula: see text] in the positive secondary ion spectrum and [Formula: see text] in the negative spectrum where the valence of Zn is + 2 and that of O is - 2. Fragment analysis in gallium-doped ZnO (GZO) films can give insights into the bonding of the elements in this important semiconductor. Fragment analysis of 1 and 7 wt% GZO films shows that only the negative ion fragments obey the FAR rule where ZnO, ZnO, ZnO and ZnO ion fragments appear. In the positive polarity, subdued peaks from out-of-the-rule ZnO, ZnO and ZnO ion fragments are observed. The Ga ion peaks are present in both the positive and negative spectra. The secondary ion spectra of undoped ZnO also shows consistency with the FAR rule. This implies that Ga doping even in amounts that exceed the ZnO lattice limit of solubility does not affect the compliance with the FAR rule.
飞行时间二次离子质谱碎片分析仍然是一项具有挑战性的任务。碎片出现规律（FAR）规则对于诸如ZnO之类的二元化合物特别有用。以ZnO形式出现的离子碎片在正二次离子谱中遵循规则[公式：见正文]，在负谱中遵循规则[公式：见正文]，其中Zn的化合价为 +2，O的化合价为 -2。对掺镓氧化锌（GZO）薄膜进行碎片分析可以深入了解这种重要半导体中元素的键合情况。对1 wt%和7 wt%的GZO薄膜进行碎片分析表明，只有负离子碎片遵循FAR规则，出现了ZnO、ZnO、ZnO和ZnO离子碎片。在正极性下，观察到来自不符合规则的ZnO、ZnO和ZnO离子碎片的微弱峰。Ga离子峰在正谱和负谱中均有出现。未掺杂ZnO的二次离子谱也与FAR规则一致。这意味着即使Ga的掺杂量超过了ZnO晶格的溶解度极限，也不会影响对FAR规则的遵循。
