Title :
A study on silicon nodules due to the Si precipitation in wafer fabrication
Author :
Hua, Y.N. ; Redkar, Shailesh ; An, L.H. ; Ang, G.B.
Author_Institution :
Chartered Semicond. Mfg Ltd., Singapore
Abstract :
In this paper, silicon nodules due to Si precipitation were investigated in wafer fabrication. Line inspection found particle contamination on bondpads and large metal 1 lines of some wafers. Cross sectional SEM results showed that some nodules were found in the metal 1 layer. EDX analysis confirmed that they were Si nodules as a high Si peak was detected on the nodules. These nodules had resulted in open failure in some metal lines. Based on the failure analysis results, we concluded that the silicon nodules were due to silicon precipitation. The preventive actions taken were to check the target if the Si value in Al exceeds the normal value, to control the parameter strictly during metal deposition and to reduce the thermal cycles after metal deposition
Keywords :
X-ray chemical analysis; elemental semiconductors; failure analysis; inspection; integrated circuit interconnections; integrated circuit metallisation; integrated circuit reliability; integrated circuit testing; precipitation; scanning electron microscopy; silicon; surface contamination; thermal stresses; Al; Al:Si value; EDX analysis; Si; Si nodules; Si peak detection; Si precipitation; bondpads; cross sectional SEM; failure analysis; line inspection; metal 1 layer nodules; metal 1 lines; metal deposition; metal lines; open failure; parameter control; particle contamination; preventive actions; silicon nodules; silicon precipitation; thermal cycles; wafer fabrication; Artificial intelligence; Atom optics; Coatings; Contamination; Etching; Fabrication; Failure analysis; Inspection; Silicon; Wafer bonding;
Conference_Titel :
Semiconductor Electronics, 2000. Proceedings. ICSE 2000. IEEE International Conference on
Conference_Location :
Guoman Port Dickson Resort
Print_ISBN :
0-7803-6430-9
DOI :
10.1109/SMELEC.2000.932444
