Browsing by Author "Pan, TM"

Now showing 1 - 16 of 16

A one-step single-cleaning solution for CMOS processes
(2003-09-01)
Chao, TS
;
Yeh, CH
;
Pan, TM
;
Lei, TF
;
Li, YH
In this paper, we demonstrate a one-step single-cleaning solution to replace the conventional RCA two-step cleaning method for complementary metal oxide semiconductor (CMOS) processes. We found the performance of devices fabricated using this new recipe is comparable or even better than that of devices fabricated using the conventional RCA method. The benefits of this method are more efficient removal of contaminants, improved driving current of devices, simpler processing, fewer steps in cleaning, time savings, reduction of cost and of chemical waste, and reduced impact on the environment. (C) 2003 The Electrochemical Society.
Characterization of ultrathin oxynitride (18-21 angstrom) gate dielectrics by NH3 nitridation and N2O RTA treatment
(2001-05-01)
Pan, TM
;
Lei, TF
;
Wen, HC
;
Chao, TS
;
電子工程學系及電子研究所
In this paper, we developed a new method to grow robust ultrathin oxynitride (E-OT = 18 Angstrom) film with effective dielectric constant of 7.15. By NH3-nitridation of Si substrate, grown ultrathin Si3N4 with N2O annealing shows excellent electrical properties in terms of significant lower leakage current, very low bulk trap density and trap generation rate, and high endurance in stressing, In addition, this oxynitride film exhibits relatively weak temperature dependence due to a Fowler-Nordheim (FN) tunneling mechanism. This dielectric film appears to be promising for future ultralarge scale integrated (ULSI) devices.
Comparison of novel cleaning solutions, with various chelating agents for post-CMP cleaning on poly-Si film
(2001-11-01)
Pan, TM
;
Lei, TF
;
Ko, FH
;
Chao, TS
;
Chiu, TH
In this study, various cleaning solutions containing chelating agents with carboxyl acid group (-COOH), such as ethylenediaminetetraacetic acid, citric acid and oxalic acid, were developed for post-poly-Si CMP cleaning. The chelating agent and tetramethylammonium hydroxide (TMAH) were simultaneously added into 2% ammonium hydroxide alkaline solution to promote the removal efficiency on particles and metallic impurities. The effectiveness of various cleaning recipes and their interaction mechanism with poly-Si surface were studied. We could explain the surface behavior of various cleaning solutions by the different molecular size and charge of chelating agents. Based on the mechanism, the behavior of surface particle and metallic impurity can be realized. The co-existence of TMAH with citric acid or oxalic acid in the alkaline cleaning solutions can significantly enhance the electrical property for the capacitor.
Comparison of ultrathin CoTiO3 and NiTiO3 high-k gate dielectrics
(2001-03-15)
Pan, TM
;
Lei, TF
;
Chao, TS
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
High-k cobalt-titanium oxide (CoTiO3) and nickel-titanium oxide (NiTiO3) were formed by directly oxidizing sputtered Co/Ti and Ni/Ti film. Al/CoTiO3/Si3N4/Si and Al/NiTiO3/Si3N4/Si capacitor structures were fabricated and measured. The effective dielectric constant (k value congruent to 45) with buffer layer for CoTiO3 is larger than that of NiTiO3. In addition, CoTiO3 depicts excellent electrical properties at the same time. This metal oxide thus appears to be a very promising high-k gate dielectric for future ultralarge scale integrated devices. (C) 2001 American Institute of Physics.
Effects of metallic contaminants on the electrical characteristics of ultrathin gate oxides
(2005)
Pan, TM
;
Ko, FH
;
Chao, TS
;
Chen, CC
;
Chang-Liao, KS
In this paper, we describe the effects that five metallic contaminants have on the electrical property of an ultrathin gate oxide. We found that, among five metallic contaminants, Fe and Ni resulted in the lowest electric breakdown fields (E-bd) and charge-to-breakdown ratios (Q(bd)) and the highest leakage currents and interface state densities (D-it). On the other hand, Ca-contaminated devices exhibit a lower leakage current and D-it and a higher Q(bd) than did the other metals. (c) 2005 The Electrochemical Society.
Electrical characteristics of thin cerium oxide film on silicon substrate by reactive DC sputtering
(2001-09-01)
Pan, TM
;
Chien, CH
;
Lei, TF
;
Chao, TS
;
Huang, TY
Electrical proper-ties of CeO2 films prepared by reactive dc sputtering on Si(100) substrate with and without the incorporation of a thin barrier layer were investigated. X-ray diffraction spectra revealed that without the thin barrier layer, single-crystal CeO2 is formed on Si(100) substrate. At an equivalent oxide thickness of 2.8 nm, CeO2 films exhibit a leakage current which is four orders of magnitude lower than that of the conventional SiO2 film at an applied bias of 2 V. Only negligible stress-induced leakage current is observed after high field stressing. The incorporation of the thin silicon nitride buffer layer, however, degraded the crystalline structure of CeO2, accompanied by deteriorated electrical properties such as leakage current and fixed charges. CeO2 film without the barrier layer is thus attractive as the high dielectric constant gate insulator for future ultralarge scale integration devices. (C) 2001 The Electrochemical Society.
High quality interpoly dielectrics deposited on the nitrided-polysilicon for nonvolatile memory devices
(2001-07-01)
Yang, WL
;
Chao, TS
;
Cheng, CM
;
Pan, TM
;
Lei, TF
High quality interpoly dielectrics have been fabricated by using NH3 and N2O nitridation on polysilicon and deposition of tetra-ethyl-ortho-silitate (TEOS) oxide with N2O annealing. The surface roughness of polysilicon is improved and the value of weak bonds is reduced due to nitrogen incorporation at the interface, which improves the integrity of interpoly dielectrics, The improvements include a higher barrier height, breakdown strength, and charge-to-breakdown, and a lower leakage current and charge trapping rate than counterparts. It is found that this method can simutaneously improve both charge-to-breakdown (up to 20 C/cm(2)) and electric breakdown field (up to 17 MV/cm).
High quality interpoly-oxynitride grown by NH3 nitridation and N2O RTA treatment
(2001-02-01)
Pan, TM
;
Lei, TF
;
Yang, WL
;
Cheng, CM
;
Chao, TS
In this letter, a method to grow high quality interpolysilicon-oxynitride (interpoly-oxynitride) film is proposed. Samples, nitridized by NH3 with additional N2O annealing and CVD TEOS deposited on poly-oxynitride (poly-I) with RTA NaO oxidation, show excellent electrical properties in terms of very high electric breakdown field, ion; leakage current, high charge to breakdown, and low electron trapping rate. This novel film is a good candidate for an interpoly dielectric of future high density EEPROM and flash memory devices.
High quality ultrathin CoTiO3 high-k gate dielectrics
(2000-09-01)
Pan, TM
;
Lei, TF
;
Chao, TS
;
Chang, KL
;
Hsieh, KC
A novel high-k cobalt-titanium oxide (CoTiO3) was formed by directly oxidizing sputtered Co/Ti film. Al/CoTiO3/Si3N4/Si capacitor structure was fabricated and measured. The effective dielectric constant with buffered layer for CoTiO3 gate dielectric can reach as high as 40 while depicting excellent electrical properties at the same time. This novel metal oxide thus appears to be a promising high-k gate dielectric for future ultralarge scale integrated devices. (C) 2000 The Electrochemical Society. S1099-0062(00)03-095-9. All rights reserved.
High-k cobalt-titanium oxide dielectrics formed by oxidation of sputtered Co/Ti or Ti/Co films
(2001-03-05)
Pan, TM
;
Lei, TF
;
Chao, TS
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
High-k cobalt-titanium oxide (CoTiO3) film was formed by directly oxidizing sputtered Co/Ti or Ti/Co films. Al/CoTiO3/Si3N4/Si capacitor structures were fabricated and measured. Excellent electrical properties with an effective dielectric constant (i.e., k value) as high as 40 have been achieved for a CoTiO3 gate dielectric with a buffer layer. The metal-oxide thus appears to be a very promising high-k gate dielectric for future ultralarge scale integrated devices. (C) 2001 American Institute of Physics.
Novel cleaning solutions for polysilicon film post chemical mechanical polishing
(2000-07-01)
Pan, TM
;
Lei, TF
;
Chen, CC
;
Chao, TS
;
Liaw, MC
Novel cleaning solutions were developed for post-CMP process, surfactant tetra methyl ammonium hydroxide (TMAH) and/or chelating agent ethylene diamine tetra acetic acid (EDTA) were added into the diluted ammonium hydroxide (NH4OH+H2O) alkaline aqueous solution to enhance removal of metallic and organic contamination, From the experimental result, it is found that the particle and metal removal efficiency and the electrical characteristics are significantly improved for post-CMP cleaning.
Novel one-step aqueous solutions to replace pregate oxide cleans
(2004-08-01)
Pan, TM
;
Lei, TF
;
Ko, FH
;
Chao, TS
;
Chin, TH
We have developed a number of novel solutions to use for one-step pregate oxide cleaning; they are based on tetraalkylammonium hydroxides of varying alkyl chain lengths, namely tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide (TPAH), and tetrabutylammonium hydroxide (TBAH). We added these surfactants together with ethylenediaminetetraacetic acid (EDTA) into the RCA SC-1 cleaning solution to enhance the efficiency of cleaning. With the exception of the TBAH solution, the cleaning efficiency of these solutions toward particles was 4%-7% higher than that of the conventional RCA method. Our cleaning methods have better efficiency toward the removal of Fe, Na, Ca, Cu, and Mn contaminants. We found that the conventional RCA method results in 10(9)-10(10) atoms/cm(2) of Cu and Mn after cleaning. The electrical breakdown field of MOS capacitors was enhanced when using the new cleaning method. The literature model for surface adsorption and double-layer formation explains the cleaning behavior of the tetraalkylammonium ion-containing solutions. The removal of surface particles and metallic contaminants and the degree of surface roughness agree with the model's predictions. We believe that the best solution for use in one-step cleaning-one that comprises EDTA and TPAH-can replace the traditional RCA cleaning method. This new method has great potential for pregate oxide cleaning because it has the advantages of faster cycle times, lower costs, and greater efficiency.
One-step cleaning solution to replace the conventional RCA two-step cleaning recipe for pregate oxide cleaning
(2001-06-01)
Pan, TM
;
Lei, TF
;
Chao, TS
;
Liaw, MC
;
Ko, FH
This work proposes an advanced wet chemical one-step cleaning process which omits the hydrochloric acid/hydrogen peroxide/water mixture (HPM) step in RCA. A novel one-step cleaning solution had been developed for pregate oxide cleaning to replace the conventional RCA two-step cleaning recipe, which used ammonia/hydrogen peroxide (or SC-1) and HPM (or SC-2) step. Tetramethylammonium hydroxide (TMAH) and ethylenediaminetetraacetic acid (EDTA) were added into the RCA SC-1 cleaning solution to enhance cleaning efficiency. From the experimental results, the particles and metallic contamination on the bare Si wafer surface could be removed significantly by applying this one-step cleaning solution. The effectiveness of various cleaning recipes and their interaction mechanism with silicon surfaces were studied. The surface adsorption and double layer models could explain the surface behavior of TMAH solutions. Based on the model, the particle, surface roughness and metallic contaminants can be realized. It was observed that the electrical properties of metal oxide semiconductor capacitors after cleaning with this novel solution were better than those after the conventional RCA cleaning. Besides, the cleaning method combining NH4OH, tetramethylammonium hydroxide, ethylenediaminetetraacetic acid, and H2O2, at 80 degreesC for 3 min showed high performance on particle removal, metal cleaning, surface smoothness, and electrical properties. Hence, this one-step cleaning process is very promising for future large sized silicon wafer cleaning due to the advantages of time-saving, low cost, and high performance. (C) 2001 The Electrochemical Society.
Optimum conditions for novel one-step cleaning method for pre-gate oxide cleaning using robust design methodology
(2000-10-01)
Pan, TM
;
Lei, TF
;
Chao, TS
;
Liaw, MC
;
Lu, CP
A novel one-step cleaning method has been developed for pre-gate-oxide cleaning to replace the conventional RCA two-step cleaning process. Tetramethyl ammonium hydroxide (TMAH) and ethylenediamine tetraacetic acid (EDTA) are added into the RCA SC-1 cleaning solution to enhance cleaning efficiency. We adapt a robust design methodology (Genichi Taguchi method) to analyze the results of our experiments. Using this novel method, it is found that the optimum conditions are A(1)B(2)C(1)D(1) (A(1): TMAH : NH4OH = 1 : 50, B-2: EDTA concentration is 100 ppm, C-1: cleaning time is 5 min, and D-1: cleaning temperature is 60 degreesC). This novel one-step cleaning method is very promising for future large-sized silicon wafer cleaning processes because it has the advantages of reduced processing time and temperature, cost reduction due to reduced chemical usage and improved performance.
Performance evaluation of cleaning solutions enhanced with tetraalkylammonium hydroxide substituents for post-CMP cleaning on poly-Si film
(2002-06-01)
Pan, TM
;
Lei, TF
;
Ko, FH
;
Chao, TS
;
Liaw, MC
The cleaning solutions augmented with tetraalkylammonium hydroxides (TAAHs) with various chain-lengths of hydrocarbon substituents were developed for post-poly-Si chemical mechanical polishing (CMP) cleaning. The cleaning performance with respect to particle, organic, and metal removal as well as surface roughness was evaluated for a series of 3% NH4H solutions dosed with 0.26 M of a TAAH and 100 ppm of ethylenediaminetetraacetic acid (EDTA). The experimental results demonstrated that the cleaning solutions enhanced with these surfactants (TAAH) and a chelating agent (EDTA) achieved significantly better removal efficiencies of particle and metal impurities than the control solution containing 3% NH4OH only. A conceptual model involving surface adsorption and double-layer formation was used to postulate the aqueous-phase surface interactions between the tetraalkylammonium cations and the poly-Si surface, and to explain the removal mechanisms of particle and metal impurities from the surface. The improved electrical properties (current density-electric field and charge-to-breakdown characteristics) of the post-CMP capacitor after cleaning further demonstrated the reliability and feasibility of the proposed cleaning recipes. (C) 2002 The Electrochemical Society.
Robust ultrathin oxynitride dielectrics by NH3 nitridation and N2O RTA treatment
(2000-08-01)
Pan, TM
;
Lei, TF
;
Chao, TS
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
In this paper, a method to grow robust ultrathin (E-OT = 28 Angstrom) oxynitride film with effective dielectric constant of 5.7 is proposed, Samples, nitridized by NH3 with additional N2O annealing, show excellent electrical properties in terms of very low bulk trap density, low trap generation rate, and high endurance in stressing. This novel dielectric appears to be very promising for future ULSI devices.