Title :
Fluxless bonding for fine-pitch and low-volume solder 3-D interconnections
Author :
Sakuma, K. ; Toriyama, K. ; Noma, H. ; Sueoka, K. ; Unami, N. ; Mizuno, J. ; Shoji, S. ; Orii, Y.
Author_Institution :
IBM Res. - Tokyo, Yamato, Japan
Abstract :
Fluxless bonding can be used for fine-pitch low-solder-volume interconnections for three-dimensional large-scale integrated-circuit (3D-LSI) applications. Surface treatments with hydrogen radicals, formic acid, vacuum ultraviolet (VUV), and Ar plasma were evaluated as candidate methods for fluxless bonding. Three-μm-thick Sn solders were evaluated for intermetallic-compound (IMC) bonding of 3D integration as a target material for fluxless bonding. X-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES), time-of-flight secondary ion mass spectrometry (TOF-SIMS), a scanning electron microscope (SEM), and a focused ion beam scanning ion microscope (FIB-SIM) were used to examine the samples. The experiments shows solder oxides and organic contaminants on the surfaces of the micro-bumps were most effectively eliminated without flux by hydrogen radical treatment among various treatments we evaluated. Bonding strength was also improved by the hydrogen radical treatment, since the shear strength was more than 50 times stronger than that of the untreated samples.
Keywords :
Auger electron spectra; X-ray photoelectron spectra; integrated circuit bonding; ion microscopy; large scale integration; scanning electron microscopy; secondary ion mass spectra; shear strength; solders; surface treatment; three-dimensional integrated circuits; time of flight mass spectra; tin; 3D-LSI; AES; Auger electron spectroscopy; FIB-SIM; SEM; Sn; TOF-SIMS; X-ray photoelectron spectroscopy; XPS; argon plasma treatment; bonding strength; fine-pitch low-solder-volume interconnections; fluxless bonding; focused ion beam scanning ion microscopy; formic acid treatment; hydrogen radical treatment; intermetallic-compound bonding; low-volume solder 3D interconnections; microbumps; scanning electron microscopy; shear strength; size 3 mum; surface treatments; three-dimensional large-scale integrated-circuit applications; time-of-flight secondary ion mass spectrometry; vacuum ultraviolet treatment; Bonding; Copper; Plasma temperature; Surface treatment; Three dimensional displays; Tin;
Conference_Titel :
Electronic Components and Technology Conference (ECTC), 2011 IEEE 61st
Conference_Location :
Lake Buena Vista, FL
Print_ISBN :
978-1-61284-497-8
Electronic_ISBN :
0569-5503
DOI :
10.1109/ECTC.2011.5898483
