Browsing by Author "Mei, YJ"

Now showing 1 - 18 of 18

Anomalous selective tungsten growth by chemical vapor deposition
(1996)
Mei, YJ
;
Chang, TC
;
Sheu, JD
;
Yeh, WK
;
Pan, FM
Selective tungsten chemical vapor deposition (W-CVD) is one of the most attractive technique for filling deep submicron contact hole and via hole for the ULSI application. In this work, we firstly find out the anomalous selective W growth for the contact hole. The tungsten only nucleates from the side ring of the contact hole bottom. Several predeposition treatments prior to W growth can improve this anomalous feature and excellently selective W growth can be achieved. Auger electron spectroscopy (AES) is utilized to investigate the interface of Si/W. A model has been proposed to explain this anomalous selective tungsten growth.
Characterization of TiN film grown by low-pressure-chemical-vapor-deposition
(1997-10-31)
Mei, YJ
;
Chang, TC
;
Hu, JC
;
Chen, LJ
;
Yang, YL
Conformal TiN films were deposited by thermal low-pressure-chemical-vapor-deposition (LPCVD) in a rotating disk reactor, using TiCl4 and NH3 with N-2 as a dilution gas. TiN plug with 0.05 mu m contact size was achieved. No void formation was observed in the TiN plug. The result demonstrated that LPCVD-TiN can be used to fill very small contact holes. The excellent step coverage and uniformity resulted from a surface-reaction-rate-limited deposition. The resistivity of TiN film was reduced to 133 mu Omega cm by in-situ NH3 plasma post-treatment. The concentration of chlorine in the TiN him was measured to be less than 2 atomic % (at.%) by Auger electron spectroscope measurement. For Al deposited on TiN, the Al orientation was found to be dependent on the deposition method of Al film, but not on the underlying TiN orientation. (C) 1997 Elsevier Science S.A.
Disordered Si/SiGe superlattices grown by ultrahigh vacuum chemical vapor deposition
(1996-02-01)
Chang, TC
;
Yeh, WK
;
Chang, CY
;
Jung, TG
;
Tsai, WC
A series of Si/Si1-xGex disordered superlattices with various degrees of disorder were grown in an ultrahigh vacuum chemical vapor deposition system (UHV/CVD). High-resolution double-crystal X-ray diffraction (HRXRD), and conventional cross-sectional transmission electron microscopy were used to evaluate the crystalline quality of these superlattices. A dynamical X-ray simulation program was employed to analyze the experimental rocking curves, Excellent matches between experimental rocking curves and simulated ones were obtained for all superlattices with various degrees of disorder.
Effectiveness of NH3 plasma treatment in preventing wet stripper damage to low-k hydrogen silsesquioxane (HSQ)
(2001-12-01)
Chang, TC
;
Mor, YS
;
Liu, PT
;
Tsai, TM
;
Chen, CW
Wet stripper is commonly used to remove photoresist in IC integration processing. However, the high alkalinity of the wet stripper solution often leads to the hydrolysis of hydrogen silsesquioxane (HSQ) film and induces water uptake. As a result, both the leakage current and dielectric constant of HSQ increase. In this study, NH3 plasma treatment was applied to the HSQ film to form a thin nitrogen-containing layer on the HSQ surface and prevents the hydrolysis of HSQ during photoresist stripping. Dielectric degradation can be prevented by NH3 plasma treatment.
Effects of H-2 plasma treatment on low dielectric constant methylsilsesquioxane
(1999-09-01)
Chang, TC
;
Liu, PT
;
Mei, YJ
;
Mor, YS
;
Perng, TH
The quality of organic low-k methylsilsesquioxane (MSQ) film is degraded by the damage of oxygen plasma and hygroscopic behavior during photoresist stripping. In addition, the interaction between MSQ and copper is worth investigating. In this work, we have studied the H-2 plasma treatment to improve the quality and enhance the copper penetration resistance of MSQ, Experimental results show the leakage current of MSQ decreases as the H-2 plasma treatment time is increased. The dielectric constant of treated samples also remains constant (similar to 2.7). In addition, the copper diffusion resistance of MSQ film is significantly promoted. The H-2 plasma treatment can provide additional hydrogen to passivate the inner structure of porous MSQ film as well as reduce the probability of moisture uptake and interaction with Cu atoms. Therefore, the low-k dielectric properties of MSQ are significantly enhanced by H-2 plasma treatment. (C) 1999 American Vacuum Society. [S0734-211X(99)05105-7].
Eliminating dielectric degradation of low-k organosilicate glass by trimethylchlorosilane treatment
(2002-07-01)
Chang, TC
;
Liu, PT
;
Mor, YS
;
Tsai, TM
;
Chen, CW
The interaction between low-k organosilicate glass (OSG) and photoresist removal is investigated. O-2 plasma ashing and chemical wet stripper are commonly performed to remove photoresist (PR) in integrated circuit fabrication. However, O-2 plasma or wet stripper will attack function groups and cause Si-OH group formation in OSG film during PR removal processing. The Si-OH groups often lead to moisture uptake and consequently dielectric degradation will occur in OSG film. Trimethylchlorosilane (TMCS) treatment can negate the damage in the OSG film after the PR removal process. In addition, chemical TMCS can react with Si-OH groups and reduces moisture uptake so that the dielectric characteristic of OSG can be maintained. Hence, TMCS treatment is a promising method for photoresist removal. (C) 2002 American Vacuum Society.
Enhancing the resistance of low-k hydrogen silsesquioxane (HSQ) to wet stripper damage
(2001-11-01)
Chang, TC
;
Mor, YS
;
Liu, PT
;
Tsai, TM
;
Chen, CW
The interaction between low-k hydrogen silsesquioxane (HSQ) film and wet stripper was investigated. The wet stripper has been commonly used to remove photoresister in IC integration processing. However, the high content of alkalinity in the stripper solution often leads to the hydrolysis of HSQ film, forming dangling bonds in the HSQ. The dangling bonds in the HSQ film can easily react with hydroxide ion (OH-) in wet stripper solution and form Si-OH bonds. The resultant HSQ film will tend to uptake water and consequently increase both the leakage current and dielectric constant. In this study, H-plasma pre-treatment was applied to the HSQ film. The hydrogen plasma treatment passivates the HSQ surface and prevent HSQ from water uptake during photoresist stripping. Therefore, dielectric degradation can be avoided with the H-2-plasma pre-treatment. (C) 2001 Elsevier Science B.V. All rights reserved.
Improvement of low dielectric constant methylsilsesquioxane by boron implantation treatment
(2001-11-01)
Chang, TC
;
Mor, YS
;
Liu, PT
;
Tsai, TM
;
Chen, CW
The organic silsesquioxane, methylsilsesquioxane (MSQ), exhibits a low dielectric constant because of its lower film density compared with thermal oxide. In this study, boron implantation treatment is investigated in order to improve the quality of MSQ. The small size of boron atoms do not damage the chemical bonding of the MSQ film. In addition, the formation of densified surfaces after boron implantation can reduce the probability of moisture uptake into the MSQ. Therefore, the leakage current of MSQ film is significantly decreased and the low-k properties of MSQ film can be maintained. (C) 2001 Elsevier Science B.V. All rights reserved.
Light emission from the porous boron delta-doped Si superlattice
(1996-02-01)
Chang, TC
;
Yeh, WK
;
Hsu, MY
;
Chang, CY
;
Lee, CP
We report the first study on the porous boron delta-doped Si superlattice. Visible photoluminescence (PL) was observed with multiple peaks from the porous boron delta-doped Si superlattice at room temperature. In the electroluminescence (EL) experiment, a bright yellow light emission was observed from the porous boron delta-doped Si superlattices. However, a weak red light emission was also observed from the conventional porous Si which is anodized at the same etching condition. As a result, the structure of the porous boron delta-doped Si superlattice has the ability of controlling the quantum size in porous Si and enhancing the light intensity from porous Si.
Photoluminescence from ordered and disordered Si-SiGe superlattices
(1996-10-01)
Chang, TC
;
Yeh, WK
;
Mei, YJ
;
Tsai, WC
;
Chen, YF
Ordered (Ord-SL) and disordered (Dis-SL) Si-SiGe superlattices are grown using ultrahigh vacuum chemical vapour deposition (UHVCVD). The results of cross-sectional transmission electron microscopy (XTEM) and high-resolution double crystal x-ray diffraction (HRXRD) indicate that high quality Si-SiGe superlattices can be achieved. Well-defined band-edge excitonic luminescence is observed for the Si0.86Ge0.14-Si superlattice. Stronger phosoluminescence (PL) is observed for the Si-SiGe disordered superlattice compared with the corresponding Si-SiGe ordered superlattice. Furthermore, PL peak energy of the Dis-SL shifts to lower value with respect to the peak position of the corresponding Ord-SL. The stronger intensity of the no-phonon (NP) peak and the red shift of the PL peak are possibly a result of two probable mechanisms: (i) the tunnelling effect and (ii) the formation of localized states.
Photoluminescence from ordered and disordered Si-SiGe superlattices
(1996-10-01)
Chang, TC
;
Yeh, WK
;
Mei, YJ
;
Tsai, WC
;
Chen, YF
Ordered (Ord-SL) and disordered (Dis-SL) Si-SiGe superlattices are grown using ultrahigh vacuum chemical vapour deposition (UHVCVD). The results of cross-sectional transmission electron microscopy (XTEM) and high-resolution double crystal x-ray diffraction (HRXRD) indicate that high quality Si-SiGe superlattices can be achieved. Well-defined band-edge excitonic luminescence is observed for the Si0.86Ge0.14-Si superlattice. Stronger phosoluminescence (PL) is observed for the Si-SiGe disordered superlattice compared with the corresponding Si-SiGe ordered superlattice. Furthermore, PL peak energy of the Dis-SL shifts to lower value with respect to the peak position of the corresponding Ord-SL. The stronger intensity of the no-phonon (NP) peak and the red shift of the PL peak are possibly a result of two probable mechanisms: (i) the tunnelling effect and (ii) the formation of localized states.
Preventing dielectric damage of low-k organic siloxane by passivation treatment
(2002-04-01)
Chang, TC
;
Mor, YS
;
Liu, PT
;
Tsai, TM
;
Chen, CW
An organic SOG, the Hybird-Organic-Siloxane-Polymer (HOSP), has high applicability to ULSI processes, because of the low dielectric constant of about 2.5. However, the HOSP film will be damaged after photoresist removal. The function groups of HOSP will be destroyed by O-2 plasma ashing and chemical wet stripper, which leads to electrical degradation. In order to avoid the issue, H-2 plasma treatment is proposed to prevent HOSP film from photoresisit stripping damage. It is found that leakage current is decreased significantly and the dielectric constant is still maintained at a low k value even after photoresist stripping. Therefore, H-2 plasma treatment is an effective technique to enhance the resistance of HOSP film against photoresist stripping damage. (C) 2002 Elsevier Science B.V. All rights reserved.
Recovering dielectric loss of low dielectric constant organic siloxane during the photoresist removal process
(2002-08-01)
Chang, TC
;
Mor, YS
;
Liu, PT
;
Tsai, TM
;
Chen, CW
The interaction between low dielectric constant (low-k) hybrid organic siloxane polymer (HOSP) and O-2 plasma ashing has been investigated. O-2 plasma ashing is commonly performed to remove the photoresist (PR) during integrated circuit fabrication. However, dielectric loss usually occurs in the HOSP films during the PR removal process. In order to eliminate dielectric loss originating from an O-2 plasma attack, hexamethyldisilazane (HMDS) treatment is proposed to repair the damage in the HOSP film. HMDS can react with Si-OH bonds and reduce moisture uptake. Moreover, the leakage current and the dielectric constant is decreased significantly when damaged HOSP film undergoes HMDS treatment. For this reason, HMDS treatment is a promising method to apply to the photoresist removal. (C) 2002 The Electrochemical Society.
Stabilizing dielectric constant of fluorine-doped SiO2 film by N2O and NH3 plasma post-treatment
(1997-10-31)
Mei, YJ
;
Chang, TC
;
Chang, SJ
;
Pan, FM
;
Chen, MSK
Fluorine doped oxide (SiO2-xFx) films have been found to exhibit a low dielectric constant. However, the critical issue about SiO2-xFx is its low resistance to moisture which causes the dielectric constant of the film to increase with time. In this work, N2O and NH3 plasma post treatments are applied to as-deposited SiO2-xFx films. It has been observed that NH3 plasma post-treatments of SiO2-xFx are quite efficient at blocking moisture. The dielectric constant and stress values of the SiO2-xFx films after the N2O and NH3 plasma post-treatments are very stable. The disadvantage of N2O plasma post-treatment is that the dielectric constant of the SiO2-xFx film increases from 3.21 to 3.6 due to fluorine desorption from the SiO2-xFx network. On the other hand, NH3 plasma post-treatment is more efficient at blocking moisture and keeping the low dielectric constant unchanged due to surface nitridation of the SiO2-xFx film. (C) 1997 Elsevier Science S.A.
The effect of ammonia plasma treatment on low-k methyl-hybrido-silsesquioxane against photoresist stripping damage
(2001-11-01)
Chang, TC
;
Mor, YS
;
Liu, PT
;
Tsai, TM
;
Chen, CW
The integration process, low-k hybrid-organic-siloxane-polymers (HOSP) and photoresist stripping process have been investigated. The dielectric properties of HOSP films are degradated after photoresist removal. This is because photoresist stripping processes destroy the functional groups and induce moisture uptake in HOSP films. In this study, NH3-plasma treatment was used for HOSP films to form a thin nitrogen-containing layer, preventing HOSP films from O-2 plasma ashing and chemical wet stripper damage during photoresist removal. The leakage current is decreased significantly and the dielecric constant is maintained at a low value after photoresist removal. These experimental results show that NH, treatment is a promising technique to enhance the resistance of HOSP films to the photoresist stripping process. (C) 2001 Elsevier Science B.V. All rights reserved.
The novel pattern method of low-k hybrid-organic-siloxane-polymer film using X-ray exposure
(2002-12-02)
Chang, TC
;
Tsai, TM
;
Liu, PT
;
Mor, YS
;
Chen, CW
An organic low dielectric constant (low-k) material, hybrid-organic-siloxane-polymer. (HOSP), is integrated into multilevel interconnection using X-ray exposure technology. In conventional IC integration processes, photoresist (PR) stripping with O-2 plasma and wet chemical stripper is an inevitable step. However, dielectric degradation often occurs when low-k dielectrics undergo the PR stripping process. This limits the application of incorporating low-k material into semiconductor fabrication. In order to overcome the integration issue, a novel pattern method, X-ray direct patterning is proposed. In this technology, the dielectric regions illuminated by X-ray will be cross-linked, forming the desired patterns. At the same time, the regions without X-ray illumination are dissolvable in a solvent of HOSP film. Direct-patterning processes have several advantages: (1) they do not need PR to define patterns; thereby the damage from PR stripping can be eliminated, (2) the complex etching on low-k dielectrics can be eliminated, (3) the process steps are simplified. In this work, we will investigate the dielectric properties of HOSP film with X-ray curing for the first time. Additionally, a scanning electron microscope image of circle pattern was made to verify the process practicability. (C) 2002 Elsevier Science B.V. All rights reserved.
Thermal stability and interaction between SiOF and Cu film
(1996)
Mei, YJ
;
Chang, TC
;
Sheu, JD
;
Yeh, WK
;
Pan, FM
In this work, we study the thermal stability and interaction between SiOF and Cu. Blanket SiOF films with various F concentration were deposited by PE-CVD. A dielectric constant as low as 3.2 was obtained. Copper were deposited on these SiOF and a series of post-deposition anneal were performed. Dielectric constant of SiOF was measured after deposition and again after anneal. AES and SIMS depth profile are utilized to determine the interdiffusion between Cu and SiOF under different annealing conditions. Breakdown voltage and dielectric constant were determined form C-V and I-V measurement using a MIS (Cu/SiOF/p-Si) diode. This results of leakage current measurement and flat band shift measurement suggest that the fluorine in the SiOF film will retard the cu diffusion.
Uniformity of epilayer grown by ultrahigh-vacuum chemical vapor deposition
(1996-04-01)
Chang, TC
;
Yeh, WK
;
Chang, CY
;
Jung, TG
;
Tsai, WC
In this work, we explored the Ge fraction, layer thickness and dopant concentration uniformity of epilayers grown by an ultrahigh-vacuum chemical vapor deposition system (UHV/CVD). Three epilayers were grown for this study: a single epilayer of SiGe, a heavily boron doped Si epilayer and a Si/SiGe superlattice with p(+) Si cap. The uniformity in a wafer was measured to be less than +/- 1.5%. In addition, we explored the wafer-to-wafer uniformity of a strained SiGe layer. The variations in thickness and composition between two samples grown in the same run were evaluated to be +/- 1.3 and +/- 1.2%, respectively. These results show that uniform layers can be simultaneously obtained on many wafers by the UHV/CVD system.