3D stacking by hybrid bonding with low temperature solder

Author(s):  
Paing Myo ◽  
Ser Choong Chong ◽  
Ling Xie ◽  
Soon Wee Ho ◽  
Wai Hong See Toh ◽  
...  
Keyword(s):  
2012 ◽  
Vol 2012 (DPC) ◽  
pp. 1-24
Author(s):  
Michael Gallagher ◽  
Jong-Uk Kim ◽  
Eric Huenger ◽  
Kai Zoschke ◽  
Christina Lopper ◽  
...  

3D stacking, one of the 3D integration technologies using through silicon vias (TSVs), is considered as a desirable 3D solution due to its cost effectiveness and matured technical background. For successful 3D stacking, precisely controlled bonding of the two substrates is necessary, so that various methods and materials have been developed over the last decade. Wafer bonding using polymeric adhesives has advantages. Surface roughness, which is critical in direct bonding and metal-to-metal bonding, is not a significant issue, as the organic adhesive can smooth out the unevenness during bonding process. Moreover, bonding of good quality can be obtained using relatively low bonding pressure and low bonding temperature. Benzocyclobutene (BCB) polymers have been commonly used as bonding adhesives due to their relatively low curing temperature (~250 °C), very low water uptake (<0.2%), excellent planarizing capability, and good affinity to Cu metal lines. In this study, we present wafer bonding with BCB at various conditions. In particular, bonding experiments are performed at low temperature range (180 °C ~ 210 °C), which results in partially cured state. In order to examine the effectiveness of the low temperature process, the mechanical (adhesion) strength and dimensional changes are measured after bonding, and compared with the values of the fully cured state. Two different BCB polymers, dry-etch type and photo type, are examined. Dry etch BCB is proper for full-area bonding, as it has low degree of cure and therefore less viscosity. Photo-BCB has advantages when a pattern (frame or via open) is to be structured on the film, since it is photoimageable (negative tone), and its moderate viscosity enables the film to sustain the patterns during the wafer bonding process. The effect of edge beads at the wafer rim area and the soft cure (before bonding) conditions on the bonding quality are also studied. Alan/Rey ok move from Flip Chip and Wafer Level Packaging 1-6-12.


2013 ◽  
Vol 58 (9) ◽  
pp. 17-28 ◽  
Author(s):  
L. Di Cioccio ◽  
I. Radu ◽  
G. Gaudin ◽  
T. Lacave ◽  
F. Baudin ◽  
...  

Author(s):  
Fumihiro Inoue ◽  
Kimoon Park ◽  
Jaber Derakhshandeh ◽  
Bongyoung Yoo
Keyword(s):  

Author(s):  
P.P.K. Smith

Grains of pigeonite, a calcium-poor silicate mineral of the pyroxene group, from the Whin Sill dolerite have been ion-thinned and examined by TEM. The pigeonite is strongly zoned chemically from the composition Wo8En64FS28 in the core to Wo13En34FS53 at the rim. Two phase transformations have occurred during the cooling of this pigeonite:- exsolution of augite, a more calcic pyroxene, and inversion of the pigeonite from the high- temperature C face-centred form to the low-temperature primitive form, with the formation of antiphase boundaries (APB's). Different sequences of these exsolution and inversion reactions, together with different nucleation mechanisms of the augite, have created three distinct microstructures depending on the position in the grain.In the core of the grains small platelets of augite about 0.02μm thick have farmed parallel to the (001) plane (Fig. 1). These are thought to have exsolved by homogeneous nucleation. Subsequently the inversion of the pigeonite has led to the creation of APB's.


Author(s):  
S. Edith Taylor ◽  
Patrick Echlin ◽  
May McKoon ◽  
Thomas L. Hayes

Low temperature x-ray microanalysis (LTXM) of solid biological materials has been documented for Lemna minor L. root tips. This discussion will be limited to a demonstration of LTXM for measuring relative elemental distributions of P,S,Cl and K species within whole cells of tobacco leaves.Mature Wisconsin-38 tobacco was grown in the greenhouse at the University of California, Berkeley and picked daily from the mid-stalk position (leaf #9). The tissue was excised from the right of the mid rib and rapidly frozen in liquid nitrogen slush. It was then placed into an Amray biochamber and maintained at 103K. Fracture faces of the tissue were prepared and carbon-coated in the biochamber. The prepared sample was transferred from the biochamber to the Amray 1000A SEM equipped with a cold stage to maintain low temperatures at 103K. Analyses were performed using a tungsten source with accelerating voltages of 17.5 to 20 KV and beam currents from 1-2nA.


Author(s):  
P. Echlin ◽  
M. McKoon ◽  
E.S. Taylor ◽  
C.E. Thomas ◽  
K.L. Maloney ◽  
...  

Although sections of frozen salt solutions have been used as standards for x-ray microanalysis, such solutions are less useful when analysed in the bulk form. They are poor thermal and electrical conductors and severe phase separation occurs during the cooling process. Following a suggestion by Whitecross et al we have made up a series of salt solutions containing a small amount of graphite to improve the sample conductivity. In addition, we have incorporated a polymer to ensure the formation of microcrystalline ice and a consequent homogenity of salt dispersion within the frozen matrix. The mixtures have been used to standardize the analytical procedures applied to frozen hydrated bulk specimens based on the peak/background analytical method and to measure the absolute concentration of elements in developing roots.


Author(s):  
Gert Ehrlich

The field ion microscope, devised by Erwin Muller in the 1950's, was the first instrument to depict the structure of surfaces in atomic detail. An FIM image of a (111) plane of tungsten (Fig.l) is typical of what can be done by this microscope: for this small plane, every atom, at a separation of 4.48Å from its neighbors in the plane, is revealed. The image of the plane is highly enlarged, as it is projected on a phosphor screen with a radius of curvature more than a million times that of the sample. Müller achieved the resolution necessary to reveal individual atoms by imaging with ions, accommodated to the object at a low temperature. The ions are created at the sample surface by ionization of an inert image gas (usually helium), present at a low pressure (< 1 mTorr). at fields on the order of 4V/Å.


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