Testing 3D stacked ICs for post-bond partial/complete stack

Advancement of VLSI technology helps semiconductor industry to manufacture Through-silicon-via (TSV) based 3D stacked ICs (SICs). During 3D assembly, multiple partial stack tests are necessary. This paper addresses test architecture optimization for 3D stacked ICs based on multiple towers with hard dies. Two different handcrafted 3D SICs comprising of SOCs from ITC'02 benchmarks are considered and overall test time is minimized based on three algorithms -- layer-by-layer, tower-by-tower and a heuristic algorithm that are presented in this paper.

Design of through-Silicon-Via (TSV) based 3D IC is became feasible recently. Testing of TSVs is an important issue in this respect. It is a challenge to test the TSVs before the bonding of different layers so that the manufacturing defects of TSV can be identified properly. In this paper, we are trying to test the TSVs before bonding. Here we have proposed a heuristic algorithm to locate the faulty TSVs uniquely and at the same time it reduces the test time significantly for locating those faulty TSVs. Simulation results how that our algorithm achieved up to on an average 33% reduction in test time for a 20 TSV network than serial testing approach. Our algorithm also performs better in terms of est time reduction than the previous work present in the literature.

Core based three-dimensional(3D) integrated circuits (ICs) design is an emerging field of semiconductor industry that promises greater number of devices on chip, increased performance and reduced power consumption. But due to scaling in technology features these chips are more complex and hence testing of these 3D ICs is a challenging task. This paper follows a P1500-style wrapper design for 3D ICs using through silicon vias (TSVs) for testing purpose. It is assumed that the core elements are distributed over several layers of the ICs. As the number of available TSVs are limited due to small chip area, this work is intended to design balanced wrapper chains using available TSVs. In this work we have proposed a polynomial time algorithm of O(N) to design the test wrapper. The results are presented based on the ITC'02 SOC test benchmarks and compared with prior work. Obtained results show that our algorithm provides better utilization of TSVs compared to the work presented in.

Through silicon via (TSV) based 3D integrated circuits have inspired a novel design paradigm which explores the vertical dimension, in order to alleviate the performance and power limitations associated with long interconnects in 2D circuits. TSVs enable vertical interconnects across stacked and thinned dies in 3D-IC designs, resulting in reduced wirelength, footprint, faster speed, improved bandwidth, and lesser routing congestion. However, the usage of TSVs itself gives rise to many critical design challenges towards the minimization of chip delay and power consumption. Therefore, realization of the benefits of 3D ICs necessitates an early and realistic prediction of circuit performance during the early layout design stage. The goal of this thesis is to meet the design challenges of 3D ICs by providing new capabilities to the existing floorplanning framework [87]. The additional capabilities included in the existing floorplanning tool is the co-placement of TSV islands with circuit blocks and performing non-deterministic assignment of signals to TSVs. We also replace the wirelength and number of TSVs in the floorplanning cost function with the total delay in the nets. The delay-aware cost function accounts for RC delay impact of TSVs on the delay of individual signal connection, and obviates the efforts required to balance the weight contributions of wirelength and TSVs in the wirelength-aware floorplanning. Our floorplanning tool results in 5% shorter wirelength and 21% lesser TSVs compared to recent approaches. The delay in the cost function improves total delay in the interconnects by 10% - 12% compared to wirelength-aware cost function. The influence of large coupling capacitance between TSVs on the delay, power and coupling noise in 3D interconnects also offers serious challenges to the performance of 3D-IC. Due to the degree of design complexity introduced by TSVs in 3D ICs, the importance of early stage evaluation and optimization of delay, power and signal integrity of 3D circuits cannot be ignored. The unique contribution of this work is to develop methods for accurate analysis of timing, power and coupling noise across multiple stacked device layers during the floorplanning stage. Incorporating the impact of TSV and the stacking of multiple device layers within floorplanning framework will help to achieve 3D layouts with superior performance. Therefore, we proposed an efficient TSV coupling noise model to evaluate the coupling noise in the 3D interconnects during floorplanning. The total coupling noise in 3D interconnects is included in the cost function to optimize positions of TSVs and

Three dimensional (3D) integration technology, involving the vertical stacking of multiple chips using through-silicon vias (TSVs), has emerged as a promising solution to improve the performance of microelectronic devices. However, the complex structures and the consequent increase in power density exacerbate the challenge of thermal management in the device including multiple chips. In order to ensure the reliability of 3D stacked chips during operation, it is important to have a better understanding of the thermal distribution of a 3D chip stack. In this paper, a detailed analysis of 3D IC packaging from thermal reliability perspective is presented, performed by finite element simulations. The effect of the variation of structure-related parameters on steady-state temperature profiles in the stack has been analyzed, including TSVs diameter and pitch, the thickness of SiO 2 , as well as the thermal conductivity of under fill. The research provides useful insights for thermal management of 3D IC packaging.

A double-sided and ultrathin 3-D glass interposer with through package vias (TPVs) at same pitch as through silicon vias (TSVs) in silicon interposers is developed to provide a compelling alternative to 3-D IC stacking of logic and memory devices with TSVs. The 3-D IC stacking approach to achieve high bandwidth has several drawbacks, including the need for TSVs through the logic die, thermal management within the 3-D stack, and the high manufacturing cost associated with wafer-based TSV processing. This paper presents design, fabrication, and electrical characterization of small TPVs (15–40 $\mu{\rm m}$ in diameter) in 30- $\mu{\rm m}$ thin glass to achieve an ultrathin 3-D interposer. This paper also reports the first demonstration of ultrasmall TPVs in glass (15 $\mu{\rm m}$ ) with same dimensions as TSVs in silicon. The signal insertion loss and crosstalk behavior of TPVs in ultrathin glass were investigated and found to be superior to TSVs using 3-D electromagnetic simulations. In demonstrating the 3-D interposers, two process-related challenges were addressed in this paper, namely: 1) defect-free formation of ultrasmall TPV holes with diameters of 15 $\mu{\rm m}$ at 27- $\mu{\rm m}$ pitch and 2) TPV metallization with copper. The fabricated TPVs in ultrathin glass showed a good model to hardware correlation of signal transmission with insertion loss ${ at 20 GHz. The results in this paper suggest that the 3-D interposer concept can be a simpler alternative to 3-D IC stacking with TSVs to achieve high bandwidth between the logic and memory devices.

Through-silicon via (TSV)-based 3-D stacked ICs are becoming increasingly important in the semiconductor industry, yet pre-bond testing of TSVs continues to be difficult with current technologies. In this paper, we present a test and discrete Fourier transform method for pre-bond testing of TSVs using probe technology. We describe the on-die test architecture and probe technique needed for TSV testing, in which individual probe needles make contact with multiple TSVs at a time. We also describe methods for capacitance and resistance measurements, as well as stuck-at and leakage tests. Simulation results using HSPICE are presented for a TSV network. We demonstrate that we can achieve high resolution in these measurements, and therefore high accuracy in defect detection when we target one or multiple TSVs at a time. We also show that the test outcome is reliable even in the presence of process variations or multiple defective TSVs.

As planar scaling to achieve higher chip integration seems to be on the brink of saturation, three-dimensional (3D) integration has emerged as a promising technology. It is critical to have efficient early stage estimation methodologies to build high performance digital systems as well as to shorten design time. In this paper, a novel methodology is proposed which takes into account key physical effects and explores Through-Silicon-Via (TSV) placement topologies for a 2-tier 3D stack. It estimates the interconnect electrical performance and TSV area penalty across two TSV performance corners. The methodology offers flexibility in selection of the CMOS technology node and the 3D stacking level. A SystemC implementation provides for parameterizability and modeling with ease and also enables integration into a high-level system simulation framework. Using our methodology, TSV placement topologies were explored for a 7-port 3D router. Our results present optimal topologies for the router for typical 45 nm and 32 nm technology nodes. They also point out unreliable topologies and give important feedback for 3D system design.

To reduce interconnect delay and power consumption while improving chip performance, a three-dimensional integrated circuit (3D IC) has been developed with die-stacking and through-silicon via (TSV) techniques. The power supply problem is one of the essential challenges in 3D IC design because IR-drop caused by insufficient supply voltage in a 3D chip reduces the chip performance. In particular, power bumps and TSVs are placed to minimize IR-drop in a 3D power delivery network. In this paper, we propose a design methodology for 3D power delivery networks to minimize the number of power bumps and TSVs with optimum mesh structure and distribute voltage variation more uniformly by shifting the locations of power bumps and TSVs while satisfying IR-drop constraint. Simulation results show that our method can reduce the voltage variation by 29.7% on average while reducing the number of power bumps and TSVs by 76.2% and 15.4%, respectively.

In this paper, we propose a multilevel multilayer partitioning algorithm for 3D ICs application. The algorithm is based on the multilevel framework to coarsen the netlist successively. A multilayer partitioning procedure is applied on each level of partition during the un-coarsening process. The objective is to minimize the total number of Through Silicon Via (TSV) while observing the area constraint for each layer. The area of each layer is the summation of circuit area and TSV area. The partitioning algorithm is customized for the structure of 3D ICs. We utilize a FM-like data structure and identify eight critical net distributions such that after a cell move, the program can update gains very effectively. The experimental results show that the proposed algorithm can effectively produce good results with small numbers of TSV, area overhead, and area coefficient of variation for the tested industrial cases. The average area overhead is only 1.84% that shows the average white space is very small. The average area coefficient of variation is only 2.61% that shows area distribution of all layers is very uniform. The results also achieve the best average value for both number of TSVs and chip area, compared to all participating teams in “Design Partition for 3D ICs” problem in the IC/CAD 2009 contest in Taiwan.

Individual dies in 3D integrated circuits are connected using through-silicon-vias (TSVs). TSVs not only increase manufacturing cost, but also incur silicon area, delay, and power overhead. However, the effects of TSV overheads have not been studied thoroughly in the literature. In this paper, we analyze the impact of TSVs on silicon area and wirelength. We derive a new 3D wirelength distribution model considering TSV size. Based on this new prediction model, we explain the impact of several design parameters newly introduced in 3D ICs. We also present a case study to show how the model can help make early design decisions for 3D ICs.

Through silicon via (TSV) is one of the key components of the emerging 3D ICs. However, increasing number of TSVs in smaller silicon area leads to some severe negative impacts on the performance of the 3D IC. Growing signal integrity issues in TSVs is one of the major challenges of 3D integration. In this paper, different materials for the cores of the vias and the interposers are investigated to find the best possible combination that can reduce crosstalk and other losses like return loss and insertion loss in the TSVs. We have explored glass and silicon as interposer materials. The simulation results indicate that glass is the best option as interposer material although silicon interposer has some distinct advantages. For via cores three materials — copper (Cu), tungsten (W) and Cu-W bimetal are considered. From the analysis it can concluded that W would be better for high frequency applications due to lower transmission coefficient. Cu offers higher conductivity, but it has larger thermal expansion coefficient mismatch with silicon. The performance of Cu-W bimetal via would be in between Cu and W. However, W has a thermal expansion coefficient close to silicon. Therefore, bimetal Cu-W based TSV with W as the outer layer would be a suitable option for high frequency 3D IC. Here, we performed the analysis in terms of return loss, transmission coefficient and crosstalk in the vias.

Design For Test (DFT) of 3D stacked integrated circuits based on Through Silicon Vias (TSVs) is one of the hot topics in the field of test of integrated circuits. This is due to the hard test accessibility (especially for upper dies) and to the high complexity where each die can embed hundreds of IPs. In this paper we propose a DFT architecture based on IEEE P1687 to enable the test of 3D stacked ICs. The proposed test architecture allows the test at all 3D fabrication levels: pre-, mid-, and postbond levels. We present a test pattern retargeting flow using IEEE P1687 languages ICL (Instrument Connectivity Language) and PDL (Procedural Description Language), which allows easy retargeting from 2D (die-level) to 3D (stack-level). Compared to IEEE 1149.1 based 3D test architecture, our proposed 3D test architecture is more flexible and enhances test concurrency without an additional area cost.

<p>Information technology-to-internet of things may have succeeded because of fast silicon chip capability expansion. Moore's law, which reduces device size, boosted integrated circuit (IC) performance. Delay rises with highdensity connection parasitic capacitance. Interconnect delays have surpassed transistor delays and slowed progress. An alternative is required now to reduce connection latency. The third dimension is used in popular 3D IC technology IC technology requires through silicon via (TSV) for signal integrity and heat mitigation. Noise coupling hinders electrical communication between signal-carrying TSVs (aggressive TSVs) and ground TSVs (victim TSVs), a 3D IC bottleneck. TSVs must be dielectrically insulated from Si substrates to avoid electrical signal interference. Additionally, first-order modelling will confirm the suggestions. This article proposes using the nanosheet field effect transistor (NSFET) to overcome 3D IC noise coupling and complementary metal oxide semiconductor (CMOS) technology nodes. After discussing the electronic industry and sub nm, several basic metrics and criteria for developing electronic components are presented. The first technique uses Perylene-N's exceptional noise-cancelling characteristics. Second technique uses electrical TSV (ETSV), thermal TSV (TTSV), and heat source models to measure noise coupling on numerous ICs. The third proposes many noise-reducing materials. The suggested structures outperform traditional approaches.</p>

3D stacking of dies is a promising technique to allow miniaturization and performance enhancement of electronic systems. The complexity of the interconnection structures, combined with the reduced thermal spreading in the thinned dies and the poorly thermally conductive adhesives complicate the thermal behaviour of a stacked die structure. The same dissipation will lead to higher temperatures and a more pronounced temperature peak in a stacked die package compared to a single die package. Therefore, the thermal behaviour in a 3D-IC needs to be studied thoroughly. In this paper, a test vehicle to assess power dissipation in multiple hot spots and the thermal impact of TSVs, is presented. In this test vehicle, a stack of test chips with integrated heaters and temperature sensors is used to evaluate the steady state and transient temperature profile of multiple hot spots. With this experimental set-up, the thermal modelling of the 3D stacks is validated.