Globalfoundries Inc.

Advanced Micro Devices Corporation

Michael Grillberger

Matthias Lehr

Frank Feustel

Thomas Werner

Frank G Kuechenmeister

Torsten Huisinga

Kai Frohberg

Dmytro Chumakov

Katrin Reiche

Jens Hahn

Heike Berthold

Holm Geisler

Rainer Giedigkeit

Steffen Koch

In a method of forming a three-dimensional semiconductor device, a first chip is provided that includes a first substrate, a first device layer positioned on and covering the first substrate, and a first metallization system positioned on and covering the first device layer, wherein the first device layer includes a plurality of first transistor elements. A second chip is also provided and includes a second substrate, a second device layer positioned on and covering the second substrate, and a second metallization system positioned on and covering the second device layer, wherein the second device layer includes a plurality of second transistor elements. The second chip is attached to the first chip so that a heat spreading material is positioned between the first chip and the second chip and covers at least a portion of the first metallization system.

Methods of forming 3-D integrated semiconductor devices having intermediate heat spreading capabilities

In a three-dimensional chip configuration, a heat spreading material may be positioned between adjacent chips and also between a chip and a carrier substrate, thereby significantly enhancing heat dissipation capability. Furthermore, appropriately sized and positioned through holes in the heat spreading material may enable electrical chip-to-chip connections, while responding thermally conductive connectors may extend to the heat sink without actually contacting the corresponding chips.

3-D integrated semiconductor device comprising intermediate heat spreading capabilities

In a semiconductor device or test structure, appropriate heating elements, for instance in the form of resistive structures, are implemented so as to obtain superior area coverage, thereby enabling a precise evaluation of the thermal conditions within a complex semiconductor device. In particular, the device internal heating elements may allow the evaluation of hot spots and the response of a complex metallization system to specific temperature profiles, in particular at critical areas, such as edge regions in which mechanical stress forces are typically highest in contact regimes in which the package substrate and the metallization system are directly connected.

Assessing thermal mechanical characteristics of complex semiconductor devices by integrated heating systems

In a semiconductor device, through hole vias or through silicon vias (TSV) may be formed so as to include an efficient stress relaxation mechanism, for instance provided on the basis of a stress relaxation layer, in order to reduce or compensate for stress forces caused by a pronounced change in volume of the conductive fill materials of the through hole vias. In this manner, the high risk of creating cracks and delamination events in conventional semiconductor devices may be significantly reduced.

Semiconductor device comprising through hole vias having a stress relaxation mechanism

In a reflow process for connecting a semiconductor die and a package substrate, the temperature gradient and thus the thermally induced mechanical forces in a sensitive metallization system of the semiconductor die may be reduced during the cooling phase. To this end, one or more heating intervals may be introduced into the cooling phase, thereby efficiently reducing the temperature difference. In other cases, the central region may additionally be cooled by providing appropriate locally restricted mechanisms, such as a locally restricted gas flow and the like. Consequently, desired short overall process times may be obtain without contributing to increased yield losses when processing sophisticated metallization systems on the basis of a lead-free contact regime.

Reduction of mechanical stress in metal stacks of sophisticated semiconductor devices during die-substrate soldering by an enhanced cool down regime

A stress compensation region that may be appropriately positioned on a package substrate may compensate for or at least significantly reduce the thermally induced mechanical stress in a sensitive metallization system of a semiconductor die, in particular during the critical reflow process. For example, a stressor ring may be formed so as to laterally surround the chip receiving portion of the package substrate, wherein the stressor ring may efficiently compensate for the thermally induced deformation in the chip receiving portion.

Stress reduction in chip packaging by a stress compensation region formed around the chip

The metallization system of complex semiconductor devices may be evaluated in terms of mechanical integrity on the basis of a measurement system and measurement procedures in which individual contact elements, such as metal pillars or solder bumps, are mechanically stimulated, while the response of the metallization system, for instance in the form of directly measured forces, is determined in order to quantitatively evaluate mechanical status of the metallization system. In this manner, the complex material systems and the mutual interactions thereof may be efficiently assessed.

Assessing metal stack integrity in sophisticated semiconductor devices by mechanically stressing die contacts

A semiconductor chip and a package substrate may be directly connected on the basis of form closure by providing appropriately shaped complementary contact structures in the semiconductor chip and the package substrate. Consequently, solder material may no longer be required and thus any elevated temperatures during the assembly process may be avoided, which may conventionally result in significant stress forces, thereby creating damage, in particular in very complex metallization systems.

Stress reduction in chip packaging by using a low-temperature chip-package connection regime

In sophisticated semiconductor devices, densely packed metal line layers may be formed on the basis of an ultra low-k dielectric material, wherein corresponding modified portions of increased dielectric constant may be removed in the presence of the metal lines, for instance, by means of a selective wet chemical etch process. Consequently, the metal lines may be provided with desired critical dimensions without having to take into consideration a change of the critical dimensions upon removing the modified material portion, as is the case in conventional strategies.

Sophisticated metallization systems in semiconductors formed by removing damaged dielectric layers after forming the metal features

By forming a protection layer prior to the application of the planarization layer during a dual damascene strategy for first patterning vias and then trenches, enhanced etch fidelity may be accomplished. In other aspects disclosed herein, via openings and trenches may be patterned in separate steps, which may be accomplished by different etch behaviors of respective dielectric materials and/or the provision of an appropriate etch stop layer, while filling the via opening and the trench with a barrier material and a highly conductive metal may be achieved in a common fill sequence. Hence, the via opening may be formed on the basis of a reduced aspect ratio, while nevertheless providing a highly efficient overall process sequence.

Reducing patterning variability of trenches in metallization layer stacks with a low-k material by reducing contamination of trench dielectrics

By dividing a single chip area into individual sub-areas, a thermally induced stress in each of the sub-areas may be reduced during operation of complex integrated circuits, thereby enhancing the overall reliability of complex metallization systems comprising low-k dielectric materials or ULK material. Consequently, a high number of stacked metallization layers in combination with increased lateral dimensions of the semiconductor chip may be used compared to conventional strategies.

Semiconductor device including stress relaxation gaps for enhancing chip package interaction stability

By forming a large metal pad and removing any excess material thereof, a pronounced recessed surface topography may be obtained, which may also affect the further formation of a metallization layer of a semiconductor device, thereby increasing the probability of maintaining metal residues above the recessed surface topography. Consequently, by providing test metal lines in the area of the recessed surface topography, the performance of a respective CMP process may be estimated with increased efficiency.

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Radebeul, Germany

Michael Grillberger