Improved Defect Localization in Metal-Insulator-Metal Capacitors Using Nanoprobe EBIRCH Technique

The necessity of the Metal-Insulator-Metal Capacitor (MIMCAP) devices that helps electrical performance of integrated circuit (IC) has drastically increased for high performance mobile SoC applications. We investigate the magnitude of intrinsic stress employed onto C4 package depends on the MIMCAP size embedded in Silicon die. It is also found that MIMCAP can mitigate 25% stresses imposed on ULK layer in the back-end-of-line (BEOL) process. Moreover, a keen definition of keep out zone (KOZ), the space between MIMCAP as a stress relaxation, is a crtical design factor to suppress potential stresses arisen from the MIMCAP embedded C4 package. In this paper, a finite element analysis (FEA) of strain and stress analysis modeling and the benefits to electromagnetic interference for the MIMCAP embedded C4 package will be disscused from design and reliability perspectives and will show superb EMI characteristics with ondie MIMCAP.

Metal-Insulator-Metal (MIM) capacitor is one of the most common use passive component nowadays on semiconductor device. Unfortunately, its floating characteristic in semiconductor device make it difficult to further fault isolate to single faulty MIM capacitor within a group of MIM capacitor after remove the metal connection layer. A method to combine passive voltage contrast (PVC) analysis technique, focus ion beam (FIB) and platinum (Pt) coater is used to further localize the exact fail site on the defect MIM capacitor which will be presented in this paper.

Metal-insulator-metal (MIM) capacitors with lanthanum oxide (La2O3) high-κ dielectric, for potential applications in mixed-signal integrated circuit (IC), have been fabricated using a dense plasma focus device. The electrical characteristics and morphological properties of the fabricated nanodevices are studied. The MIM capacitors were further annealed to enhance the electrical properties in terms of the low leakage current density, the high capacitance density, and the improved capacitance voltage linearity. The minimum leakage current densities of ∼1.6 × 10−9 A/cm2 and ∼2.0 × 10−10 A/cm2 at −1 V are obtained along with the maximum capacitance densities of ∼17.96 fF/μm2 at 100 kHz and ∼19.10 fF/μm2 at 1 MHz, 0 V for as-fabricated and annealed MIM capacitors having 15 nm thick dielectric layers as measured using ellipsometry. The nanofilms with the minimum root mean square roughness of ∼10 nm are examined using atomic force microscopy. The results are superior compared to some other MIM capacitors and can be optimized to achieve the best electrical parameters for potential applications in radio frequency (RF)/mixed signal ICs. The high frequency C-V measurements indicate an increase in the capacitance density upon increasing the frequency which supports the possibility of potential high-frequency/RF applications of the MIM capacitors.

Electrical characterizations were needed to identify the root cause of leakage issues in IC devices. The methodology required was dependent on the failure mode obtained during testing and global or nano-scale isolations had to be implemented accordingly. As such, challenges encountered in sample preparation or due to detection methodology choices for every isolation technique have to be addressed in order to localize the defective sites.

Sputtered HfO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> and co-sputtered BZT-HfO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> dielectrics have been compared for high density metal-insulator-metal (MIM) capacitors, which are required for radio frequency and analog/mixed-signal integrated circuits. The MIM capacitor with BZT-HfO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> shows a high permittivity value of 20.8, and the small quadratic voltage coefficient of capacitance of 1830 ppm/V <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> at 100kHz compared to that with HfO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> dielectric. Further, the leakage characteristics of the capacitors with HfO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> and BZT-HfO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> dielectrics have been studied as a function of measurement temperature, and the conduction mechanisms are discussed.

Low temperature high density Si3N4 MIM capacitor technology for MMMIC and RF-MEMs applications

Secondary electron detector (SED) plays a vital role in a focused ion beam (FIB) system. A successful circuit edit requires a good effective detector. Novel approach is presented in this paper to improve the performance of such a detector, making circuit altering for the most advanced integrated circuit (IC) possible.

We have used ballistic electron emission microscopy to study the technologically important area of metal contacts to III–V semiconductors. Our samples are Au/GaAs diodes selectively damaged by focused ion beam (FIB) implantation. Implanted regions display reduced interface transmission as the implantation dose is increased above 5×1012 ions/cm2 for Au+ at 30 keV energy. Localized current–voltage measurements indicate that implanted regions have Schottky barrier heights slightly different from those of unimplanted regions. However, these differences are insufficient to account for the attenuated interface transmission. We invoke increased scattering from FIB-induced defects to explain the data. Defect sites in the Au or at the interface may scatter electrons away from the Schottky barrier, or increase inelastic scattering, both of which would lower interface transmission. The effects of several FIB related mechanisms on barrier heights and scattering are explored.

FAMn:PbI3 perovskite films were synthesized and probed mainly through electron spin resonance (ESR) spectroscopy. FAMn:PbI3 with low (~1%) Mn concentration showed a hyperfine sextet line originated from Mn++ ions. FAMn:PbI3 with high (10%) Mn concentration showed broad resonance (~500 G peak-to-peak linewidth). However, after bombardment of FAMn:PbI3 with high Mn concentration by focused ion beams (FIB), a sharp ESR peak appeared. The peak-to-peak linewidth (ΔHpp) was ~8 G regardless of the temperature. The FIB-induced defect showed Curie behavior at low temperatures (5 K - 50 K), which indicates the presence of localized electrons at the defect sites at low temperatures. The g-value increased from g = 2.0002 to 2.0016 as the temperature increased from 5 K to 50 K. Together with the ongoing search for electron spin echo (ESE), this could potentially provide a platform for realizing magnetic bits, information storage, and increased manipulation speed.

Defect-induced carbon nanoscroll formation

In this paper, a novel inspection mode of electron beam inspection (EBI) that can effectively detect buried voids in tungsten (W) plugs is reported for the first time. Buried voids in metal are a defect of interest (DOI) that cannot be captured by either optical inspection or traditional EBI modes. The detection of buried voids is achieved by using energetic electron beam (e-beam) with energy high enough to penetrate into metal and reach the buried void. By selecting desired secondary electrons to form the inspection images, strong contrast between the defective tungsten plugs and normal ones can be achieved. Failure analysis was performed on the DOI that is unique to this new EBI mode. After optical microscope locating and laser marking, we successfully recaptured DOI with scanning electron microscope (SEM) and capped the DOI with e-beam assisted platinum (Pt) deposition. Later a dual-beam focused ion beam (FIB) system was used to re-locate the Pt-capped DOI and prepare samples for transmission electron microscope (TEM). TEM images confirmed the unique DOI were buried voids in the metal plugs, which could affect resistance of interconnect in integrated circuit (IC) chip and impact the IC yield.

The focused ion beam (FIB) is a powerful piece of technology which has enabled scientific and technological advances in the realization and study of micro- and nano-systems in many research areas, such as nanotechnology, material science, and the microelectronic industry. Recently, its applications have been extended to the photonics field, owing to the possibility of developing systems with complex shapes, including 3D chiral shapes. Indeed, micro-/nano-structured elements with precise geometrical features at the nanoscale can be realized by FIB processing, with sizes that can be tailored in order to tune optical responses over a broad spectral region. In this review, we give an overview of recent efforts in this field which have involved FIB processing as a nanofabrication tool for photonics applications. In particular, we focus on FIB-induced deposition and FIB milling, employed to build 3D nanostructures and metasurfaces exhibiting intrinsic chirality. We describe the fabrication strategies present in the literature and the chiro-optical behavior of the developed structures. The achieved results pave the way for the creation of novel and advanced nanophotonic devices for many fields of application, ranging from polarization control to integration in photonic circuits to subwavelength imaging.

As the dimensions of integrated circuits (ICs) decrease into the submicron range, the problems of circuit delay and interconnect reliability become more urgent. Due to its low resistivity (1.67 μΩ cm) and high electromigration resistance, copper has received attention as a candidate metal for the ICs of the future. In addition, the focused-ion beam (FIB), with its capability for milling and deposition at linewidths of 0.1 μm or below, has proved useful as a tool for integrated IC ‘‘microsurgery.’’ FIB induced deposition of copper from a novel organometallic precursor compound, Cu(hfac)TMVS, has been achieved using 25–35 keV Ga+ ions from a liquid metal ion source. Submicron copper lines deposited at room temperature from this precursor exhibit resistivities as low as 50 μΩ cm; a sharp drop in these values is noted for deposition above 67 °C, and deposition on a substrate heated above ∼100 °C yields resistivities near those of pure bulk copper. Composition analysis by Auger electron spectroscopy shows the high temperature deposition to be nearly pure copper. Deposition yields of 14 copper atoms per incident Ga+ ion have been obtained on both silicon and silicon dioxide substrates, with growth rates of up to 2.2 nm/s at an average ion current density of 200 μA/cm2. The quality and microstructure of the deposited film seems to be inextricably tied to the ability of the carbon-containing by-product molecules to desorb from the growing film. For instance, high-temperature deposition results in a low resistivity film with few impurities, most likely because this condition allows greater by-product desorption. Under the proper conditions, this particular precursor compound shows great promise for use in the FIB induced deposition of low resistivity, submicron interconnects on ICs for repair processes.

Fault localization in a 3D test assembly using voltage contrast imaging

Refractory metals are commonly seen in many structures and defects in Si based semiconductors integrated circuits (ICs). Such defect can be easily identified under x-ray microanalysis conducted with high-beam energies. However, these analyses are typically carried out with a low beam energy to optimize spatial resolution and mitigate background noise from the sample. X-ray microanalysis at low beam energies will generate only M-line X-rays and many of these overlap with the Si-K X-rays line, like W-M line and Ta-M line. In this paper, energy dispersive X-ray (EDX) analysis was study at both low beam energy (5 kV) and high beam energy (15 kV) on un-landed tungsten plug embedded in Silicon dioxide of a post FIB sample. To reduce background noise during high beam energy EDX analysis, further study was carried out on thin slices of samples of about 100nm to a few hundred nanometers prepared by focused ion beam (FIB).