Characterization of Plasma Damage in Low-k Films by TVS Measurements

2009 ◽  
Vol 1156 ◽  
Author(s):  
Ivan Ciofi ◽  
Mikhail R. Baklanov ◽  
Giovanni Calbo ◽  
Zsolt Tőkei ◽  
Gerald Beyer
Keyword(s):  
High Temperature ◽  
Exposure Time ◽  
Ftir Spectra ◽  
Material Structure ◽  
Electrical Measurements ◽  
Hydrophobic Properties ◽  
Plasma Damage ◽  
K Value ◽  
Voltage Sweep ◽  
Low K

AbstractWe evaluated Triangular Voltage Sweep (TVS) measurements as a technique to characterize plasma damage in low-k films. Blanket wafers with low-k films of different porosity and k value were prepared. Our samples included an SiOC:H material with 7% porosity and k value of 3.0, deposited on 200mm wafers, and two SiOC:H materials with 25% porosity and k value of 2.5, deposited on 300mm wafers. Before deposition, a thin layer of dry thermal oxide (2 – 5 nm) was grown on the n-type wafers to stabilize the silicon interface. After deposition, low-k films were exposed to N2/H2 plasma for different times in order to induce different degree of plasma damage. Untreated low-k films were always included as a reference. For electrical measurements, metal dots were deposited on pieces to fabricate Metal-Insulator-Semiconductor capacitors.TVS measurements were performed at 190°C on the different samples. On samples exposed to N2/H2 plasma, we detected a current peak in the TVS trace, whose magnitude increased with exposure time to plasma. No peaks were detected on untreated films. This indicates that TVS measurements are sensitive to plasma damage. Furthermore, TVS results correlated well with FTIR spectra that showed increasing damage and H2O uptake with increasing exposure time to plasma. We conclude that TVS measurements are suitable for characterizing the degree of plasma damage in low-k films and complement well materials analysis, because with the help of TVS a link to leakage properties can be made. As an application, we used TVS measurements for evaluating restoration of plasma damaged low-k films by long N2-bake at high temperature. Wafer pieces from each sample were baked at 350°C for 4h30min in N2 atmosphere. A few pieces were measured immediately after baking. The remaining pieces were either left exposed to ambient for a few days or dipped in deionized H2O for a few hours to evaluate recovery of hydrophobic properties. The different treatments (N2-bake, exposure to ambient, H2O dipping) were always performed on blanket wafer pieces. Metal dots for electrical measurements were only deposited after the treatment. CV and FTIR measurements were performed before and after treatments to evaluate change in k-value and material structure, respectively. Our data show that long N2-bake at high temperature can partially restore damaged low-k films. The magnitude of the damage-related TVS peak was significantly reduced after heat treatment and remained stable even after H2O dipping. CV measurements performed on baked pieces after 6 days of exposure to ambient showed a reduced k-value. Consistently, FTIR spectra showed a significant reduction of H2O content soon after baking. The materials remained stable over several days and only minor reincorporation of H2O occurred after exposure to ambient or H2O dipping. Therefore, long N2-bake at high temperature can partially restore leakage (TVS), k-value (CV) and hydrophobic properties (FTIR) of damaged low-k films.

Optimization of low-k UV Curing: Effect of Wavelength on Critical Properties of the Dielectrics

2009 ◽  
Vol 1156 ◽  
Author(s):  
German Aksenov ◽  
David De Roest ◽  
Patrick Verdonck ◽  
Premysl Marsik ◽  
Denis Shamiryan ◽  
...  
Keyword(s):  
Monochromatic Light ◽  
Matrix Material ◽  
Uv Curing ◽  
Porous Films ◽  
Plasma Damage ◽  
K Value ◽  
The Matrix ◽  
Different Temperatures ◽  
Curing Light ◽  
Low K

AbstractThe results of recent investigations show that after UV curing of CVD SiCOH low-k films deposited with organic material (porogen) some amount of the porogen remains in the cured films in the form of non-volatile graphitized phase, known as “porogen residue”. These residues could influence leakage current and reliability. The goal of the present work is investigation of the different parameters of UV curing that can influence amount of the porogen residue. In this work we focused generally on the study of the amount of porogen residues as function of the wavelength of curing light and the porosity of the material (amount of deposited porogen). To study the curing dependence on the wavelength, we compared optical properties (measured by spectroscopic ellipsometry) and IR adsorption (measured by FTIR) of samples cured by 172 nm monochromatic light (lamp A) with samples cured by broadband source with wavelength more than 200 nm (lamp B). To understand how the amount of porogen residue depends on the amount of deposited porogen (porosity), three films with different k-value were deposited: a film with k = 3 deposited without porogen and two porogen-based low-k with target k-value of 2.5 and 2.3. Furthermore, taking into account that He/H2 plasma effectively removes the porogen residues from porous films without any plasma damage of the matrix material, we exposed the films to that plasma. Then these films were cured by broadband lamp at different temperatures and amount of porogen residues was measured by ellipsometry. It was found that He/H2 plasma cannot fully remove the porogen and causes film shrinkage. The Subsequent UV curing does not produce significant changes.

Integration of ALD-TaN Liners on Nanoporous Dielectrics

2005 ◽  
Vol 863 ◽  
Author(s):  
Bum Ki Moon ◽  
Tadashi Iijima ◽  
Sandra Malhotra ◽  
Andrew Simon ◽  
Thomas Shaw ◽  
...  
Keyword(s):  
Color Change ◽  
Average Pore Size ◽  
Barrier Properties ◽  
Optical Microscope ◽  
Deep Penetration ◽  
Electrical Measurements ◽  
Plasma Damage ◽  
Average Pore ◽  
K Value ◽  
Interlayer Dielectric

AbstractUltra-thin ALD-TaN/PVD-Ta liners have been developed to prevent Cu diffusion into porous interlayer dielectric (ILD) materials envisioned for future copper interconnections. The porous ultra-lowk(p-ULK) film is prepared using the spin-on method, and typical k-value and the average pore size of p-ULK used in this paper are 2.3 and 2-3 nm, respectively. Interaction and phenomena at the ILD/ALD-TaN interface have been investigated, and the electrical measurements of samples with a bi-layered ALD-TaN/PVD-Ta barrier were performed after completing the metallization and CMP process.A deep penetration of ALD-TaN was observed on the as-deposited p-ULK, which is due to the interconnected pore structures. However, the surface of the p-ULK is drastically changed after the etch process, where changes are attributed to plasma damage and re-deposition of etched species. Pores can therefore be sealed during the etch process. Furthermore, the plasma damage makes the sidewall more hydrophilic, which may promote the growth of ALD-TaN layer. Based on EELS and EDS profiles, there is no signature of TaN penetration into the etched p-ULK at M1 level with a sharp Ta peak, which indicates excellent stability of ultra-thin ALD-TaN liner.An oxidation test in air ambient and at elevated temperature confirmed the barrier properties of the stacked ALD-TaN/PVD-Ta layers. Any weak point in the barrier allows the Cu to oxidize and to make a color change under an optical microscope. However, all of our samples showed no color change, which implies that the barrier is very uniform and stable. Electrical properties measured at M1 showed excellent results. Our results demonstrate the ability to successfully integrate ALD-TaN barriers with a nanoporous ULK film.

Evaluation of plasma damage in ultra-low-k materials with cap film using “extracted k-value” method

2008 ◽  
Vol 85 (10) ◽  
pp. 2107-2110 ◽  
Author(s):  
Hyoh Takahashi ◽  
Yoshio Takimoto ◽  
Makoto Masuda ◽  
Yoshito Ando
Keyword(s):  
Plasma Damage ◽  
K Value ◽  
Low K

The Effect of Plasma Damage on the Material Composition and Electrical Performance of Different Generations of SiOC(H) Low k Films

2006 ◽  
Vol 914 ◽  
Author(s):  
Aurelie Humbert ◽  
Didem Ernur Badaroglu ◽  
Romano J.O.M Hoofman
Keyword(s):  
Moisture Absorption ◽  
Chemical Degradation ◽  
Electrical Performance ◽  
Plasma Damage ◽  
K Value ◽  
Angle Measurements ◽  
Plasma Treatments ◽  
Contact Angle Measurements ◽  
Low K

AbstractThe degradation of SiOC(H) low-k films upon plasma treatments has been investigated. Three generations of SiOC(H) low-k dielectrics (k=3.0, k=2.6 and k=2.3) were used. The low-k materials have been exposed to N2O, NH3, O2, H2, He, Ar and N2 based plasmas, representing the most commonly-used plasmas during interconnect integration. For all plasma-treated samples, an increase in k-value and decrease in breakdown voltage was observed. These observations could be attributed to chemical degradation, in particular to carbon depletion and OH-bond formation. The latter leads to moisture adsorption, which was confirmed by contact angle measurements and FTIR spectra. The N2O plasma treatment was found to be the most aggressive for all low-k dielectrics studied. It drastically increases the k-value and the leakage current and results in complete carbon removal on the top-surface. This effect is most pronounced on the most porous material. On the other hand, an in-situ helium plasma shortly after low-k deposition enhances the resistance to chemical degradation upon exposure to other plasmas, even for the most aggressive ones. For the argon and reactive pre-clean plasmas, only small compositional changes were observed. In conclusion, it can be said that not only the plasma treatments have to be tuned in accordance with the low k integration requirements, but also attention has to be paid to limit moisture absorption during integration.

Impact of Metal Pad Etch-Induced Plasma Damage on Dynamic Retention Time Degradation during High Temperature Stress in High Density DRAM Technology

2005 ◽  
Author(s):  
D-J Kim ◽  
I-G Kim ◽  
J-Y Noh ◽  
H-J Lee ◽  
S-H Park ◽  
...  
Keyword(s):  
High Temperature ◽  
Temperature Stress ◽  
Retention Time ◽  
High Temperature Stress ◽  
High Density ◽  
Cell Junction ◽  
Antenna Effect ◽  
Plasma Damage ◽  
Root Cause ◽  
Wafer Processing

Abstract As DRAM technology extends into 12-inch diameter wafer processing, plasma-induced wafer charging is a serious problem in DRAM volume manufacture. There are currently no comprehensive reports on the potential impact of plasma damage on high density DRAM reliability. In this paper, the possible effects of floating potential at the source/drain junction of cell transistor during high-field charge injection are reported, and regarded as high-priority issues to further understand charging damage during the metal pad etching. The degradation of block edge dynamic retention time during high temperature stress, not consistent with typical reliability degradation model, is analyzed. Additionally, in order to meet the satisfactory reliability level in volume manufacture of high density DRAM technology, the paper provides the guidelines with respect to plasma damage. Unlike conventional model as gate antenna effect, the cell junction damage by the exposure of dummy BL pad to plasma, was revealed as root cause.

scholarly journals High-temperature Inhibition of Flowering of Phalaenopsis and Doritaenopsis Orchids

HortScience ◽  
2009 ◽  
Vol 44 (5) ◽  
pp. 1271-1276 ◽  
Author(s):  
Linsey A. Newton ◽  
Erik S. Runkle
Keyword(s):  
High Temperature ◽  
Exposure Time ◽  
Flowering Plants ◽  
Night Temperature ◽  
High Temperature Exposure ◽  
Plant Leaf ◽  
Potted Plants ◽  
Temperature Exposure

Phalaenopsis orchids require a day temperature of 26 °C or less to initiate inflorescences, whereas the night temperature has little or no effect on inflorescence initiation. We determined the duration of high temperature required each day to prevent inflorescence initiation of four Phalaenopsis and Doritaenopsis clones. In Years 1 and 2, mature potted plants were grown in separate greenhouse sections with five daily durations at 29 °C: 0, 4, 8, 12, or 24 h. The high temperature was centered in the 16-h photoperiod (0600 hr to 2200 hr) and the remainder of the day was at 20 °C. Exposure to 29 °C for 8 h or longer inhibited inflorescence initiation of Phalaenopsis Miva Smartissimo × Canberra ‘Mosella’ and Phalaenopsis Brother Pink Mask × Brother Success ‘Explosion’, but Phalaenopsis Baldan's Kaleidoscope ‘Golden Treasure’ and Doritaenopsis ‘Newberry Parfait’ required exposure to 29 °C for 12 h or longer to inhibit inflorescence initiation. Flowering was completely suppressed only when high-temperature exposure time was continual for Doritaenopsis ‘Newberry Parfait’ and Phalaenopsis Baldan's Kaleidoscope ‘Golden Treasure’ and 12 h for Phalaenopsis ‘Mosella’. Plant leaf span generally increased as duration of exposure to 29 °C increased, but high-temperature exposure had few or no significant effects on flowering characteristics of flowering plants. These studies indicate that as few as 8 h of high temperature can prevent flowering of some Phalaenopsis hybrids, whereas others require greater than 12 h of high-temperature exposure.

CVD Boron Carbo-Nitride as Pore Sealant for Ultra Low-K Interlayer Dielectrics

2005 ◽  
Vol 863 ◽  
Author(s):  
P. Ryan Fitzpatrick ◽  
Sri Satyanarayana ◽  
Yangming Sun ◽  
John M. White ◽  
John G. Ekerdt
Keyword(s):  
Photoelectron Spectroscopy ◽  
Depth Profiling ◽  
Chemical Vapor ◽  
K Value ◽  
X Ray ◽  
Dimethylamine Borane ◽  
The Stability ◽  
Low K ◽  
Secondary Ion ◽  
Sims Depth Profiling

AbstractBlanket porous methyl silsesquioxane (pMSQ) films on a Si substrate were studied with the intent to seal the pores and prevent penetration of a metallic precursor during barrier deposition. The blanket pMSQ films studied were approximately 220 nm thick and had been etched and ashed. When tantalum pentafluoride (TaF5) is exposed to an unsealed pMSQ sample, X-ray photoelectron spectroscopy (XPS) depth profiling and secondary ion mass spectroscopy (SIMS) depth profiling reveal penetration of Ta into the pores all the way to the pMSQ / Si interface. Boron carbo-nitride films were grown by thermal chemical vapor deposition (CVD) using dimethylamine borane (DMAB) precursor with Ar carrier gas and C2H4 coreactant. These films had a stoichiometry of BC0.9N0.07 and have been shown in a previous study to have a k value as low as 3.8. BC0.9N0.07 films ranging from 1.8 to 40.6 nm were deposited on pMSQ and then exposed to TaF5 gas to determine the extent of Ta penetration into the pMSQ. Ta penetration was determined by XPS depth profiling and sometimes SIMS depth profiling. XPS depth profiling of a TaF5 / 6.3 nm BC0.9N0.07 / pMSQ / Si film stack indicates the attenuation of the Ta signal to < 2 at. % throughout the pMSQ. Backside SIMS of this sample suggests that trace amounts of Ta (< 2 at. %) are due to knock-in by Ar ions used for sputtering. An identical film stack containing 3.9 nm BC0.9N0.07 was also successful at inhibiting Ta penetration even with a 370°C post-TaF5 exposure anneal, suggesting the stability of BC0.9N0.07 to thermal diffusion of Ta. All BC0.9N0.07 films thicker than and including 3.9 nm prevented Ta from penetrating into the pMSQ.

High temperature water as a clean and etch of low-k and SiO2 films

2018 ◽  
Vol 196 ◽  
pp. 54-58
Author(s):  
Joshua D. Barclay ◽  
Oseoghaghare Okobiah ◽  
Lu Deng ◽  
Tina Sengphanlaya ◽  
Jincheng Du ◽  
...  
Keyword(s):  
High Temperature ◽  
Sio2 Films ◽  
High Temperature Water ◽  
Low K ◽  
Temperature Water

Characterization of Silicone Gel for High Temperature Encapsulation in High Voltage WBG Power Modules

2017 ◽  
Vol 2017 (1) ◽  
pp. 000312-000317
Author(s):  
Adam Morgan ◽  
Xin Zhao ◽  
Jason Rouse ◽  
Douglas Hopkins
Keyword(s):  
High Temperature ◽  
Thermal Aging ◽  
Dielectric Strength ◽  
Material Structure ◽  
Power Module ◽  
Leakage Currents ◽  
Test Vehicle ◽  
Silicone Gel ◽  
Power Modules ◽  
Silicone Gels

Abstract One of the most important advantages of wide-bandgap (WBG) devices is high operating temperature (&gt;200°C). Power modules have been recognized as an enabling technology for many industries, such as automotive, deep-well drilling, and on-engine aircraft controls. These applications are all required to operate under some form of extreme environmental conditions. Silicone gels are the most popular solution for the encapsulation of power modules due to mechanical stress relief enabled by a low Young's modulus, electrical isolation achieved due to high dielectric strength, and a dense material structure that protects encapsulated devices against moisture, chemicals, contaminants, etc. Currently, investigations are focused on development of silicone gels with long-term high-temperature operational capability. The target is to elevate the temperature beyond 200°C to bolster adoption of power modules in the aforementioned applications. WACKER has developed silicone gels with ultra-high purity levels of &lt; 2ppm of total residual ions combined with &gt; 200°C thermal stability. In this work, leakage currents through a group of WACKER Chemie encapsulant silicone gels (A, B, C) are measured and compared for an array of test modules after exposure to a 12kV voltage sweep at room temperature up to 275°C, and thermal aging at 150°C for up to more than 700 hours. High temperature encapsulants capable of producing leakage currents less than 1μA, are deemed acceptable at the given applied blocking voltage and thermal aging soak temperature. To fully characterize the high temperature encapsulants, silicone gel A, B, and C, an entire high temperature module is used as a common test vehicle. The power module test vehicle includes: 12mil/40mil/12mil Direct Bonded Copper (DBC) substrates, gel under test (GUT), power and Kelvin connected measurement terminals, thermistor thermal sensor to sense real-time temperature, and 12mil Al bonding wires to manage localized high E-Fields around wires. It was ultimately observed that silicone gels B and C were capable of maintaining low leakage current capabilities under 12kV and 275°C conditions, and thus present themselves as strong candidates for high-temperature WBG device power modules and packaging.

Changes of UV Optical Properties of Plasma Damaged Low-k Dielectrics for Sidewall Damage Scatterometry

2008 ◽  
Vol 1079 ◽  
Author(s):  
Premysl Marsik ◽  
Adam Urbanowicz ◽  
Klara Vinokur ◽  
Yoel Cohen ◽  
Mikhail R Baklanov
Keyword(s):  
Thin Film ◽  
Optical Properties ◽  
Optical Model ◽  
Concentration Profiles ◽  
Atomic Concentration ◽  
Plasma Damage ◽  
Tof Sims ◽  
Plasma Treatments ◽  
Water Based ◽  
Low K

ABSTRACTPorous low-k dielectrics were studied to determine the changes of optical properties after various plasma treatments for development of scatterometry technique for evaluation of the trench/via sidewall plasma damage. The SiCOH porogen based low-k films were prepared by PE-CVD. The deposited and UV-cured low-k films have been damaged by striping O2Cl2, O2, NH3 and H2N2 based plasmas and CF4/CH2F2/Ar etching plasma. Blanket wafers were studied in this work for the simplicity of thin film optical model. The optical properties of the damaged low-k dielectrics are evaluated the using various angle spectroscopic ellipsometry in range from 2 to 9 eV. Multilayer optical model is applied to fit the measured quantities and the validity is supported by other techniques. The atomic concentration profiles of Si, C, O and H were stated by TOF-SIMS and changes in overall chemical composition were derived from FTIR. Toluene and water based ellipsometric porosimetry is involved to examine the porosity, pore interconnectivity and internal hydrophilicity.

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