Browsing by Author "Li, LJ"

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Effects of O-2- and N-2-plasma treatments on copper surface
(2004-11-01)
Chiang, CC
;
Chen, MC
;
Li, LJ
;
Wu, ZC
;
Jang, SM
In this work, we investigate the effects of oxygen (O-2) and nitrogen (N-2) plasma treatments on the copper surface of aluminum/amorphous silicon-nitricarbide/copper (Al/alpha-SiCN/Cu) metal-insulator-metal (MIM) capacitors with respect to their leakage current and breakdown field. It is found that both the O-2- and N-2-plasma treatments have an adverse effect on the leakage current and breakdown field of MIM capacitors. The MIM capacitors with their Cu surfaces subjected to O-2- or N-2-plasma treatment exhibit a room-temperature leakage current density several orders of magnitude larger than that of the sample without plasma treatment at the same applied electric field. The room-temperature breakdown fields of the MIM capacitors with O-2- and N-2-plasma-treated Cu surfaces are 3.8 and 3.2 MV/cm, respectively, while that of the control sample without plasma treatment is 7.8MV/cm. The increased leakage currents and degraded breakdown fields of the O-2- and N-2-plasma-treated samples are attributed, respectively, to the presence of metastable Cu-O oxide and Cu-N azide at the Cu surfaces.
Leakage mechanism in Cu damascene structure with methylsilane-doped low-K CVD oxide as intermetal dielectric
(2001-06-01)
Wu, ZC
;
Chiang, CC
;
Wu, WH
;
Chen, MC
;
Jeng, SM
This letter investigates the leakage mechanism in the Cu damascene structure with methylsilane-doped low-k CVD organosilicate glass (OSG) as the intermetal dielectric (IMD), The leakage between Cu lines was found to be dominated by the Frenkel-Poole (F-P) emission in OSG for the structure using a 50-nm SiC etching stop layer (ESL), In the structure using a 50-nm SiN ESL, the leakage component through SiN also made a considerable contribution to the total leakage in addition to the bulk leakage from trapped electrons in OSG, An appropriate ESL of sufficient thickness is essential to reduce the leakage through the ESL if an ESL is used in the Cu damascene integration scheme.
Physical and barrier properties of amorphous silicon-oxycarbide deposited by PECVD from octamethylcyclotetrasiloxane
(2004)
Chiang, CC
;
Chen, CC
;
Li, LJ
;
Wu, ZC
;
Jang, SM
This work investigates the thermal stability and physical and barrier properties for three species of amorphous silicon-oxycarbide (alpha-SiCO) dielectric barrier films, deposited by plasma-enhanced chemical vapor deposition (PECVD), to copper (Cu) diffusion using octamethylcyclotetrasiloxane precursor and helium (He) carrier gas with and without oxygen (O-2) reaction gas. The alpha-SiCO dielectric barrier film deposited by PECVD without O-2 reaction gas exhibits a low k-value of 2.8, thermally stable at temperatures up to 550 degreesC, excellent moisture resistance, and superb Cu barrier property until 400 degreesC. With the addition of O-2 reaction gas during the dielectric deposition process, the dielectric constant of the alpha-SiCO dielectric barrier films increases with increasing flow rate of O-2 reaction gas. Increasing flow rate of O-2 reaction gas during the deposition of the alpha-SiCO dielectric barrier films also degrades the thermal stability and moisture resistance of the dielectric barrier films. Moreover, the addition of O-2 reaction gas also results in a degraded Cu barrier property of dielectric films. (C) 2004 The Electrochemical Society.
TDDB reliability improvement in Cu damascene by using a bilayer-structured PECVD SiC dielectric barrier
(2002)
Chiang, CC
;
Chen, MC
;
Wu, ZC
;
Li, LJ
;
Jang, SM
This work investigates the thermal stability and barrier characteristics of two species of silicon carbide dielectric films, alpha-SiCN with a dielectric constant of 4.9 and alpha-SiC with a dielectric constant of 3.8. The TDDB lifetime of Cu damascene metallization structure is greatly improved by using a alpha-SiCN/alpha-SiC bilayer dielectric stack as the etching stop layer (ESL). This improvement is presumably due to the alpha-SiC dielectric's lower leakage current, absence of nitridation on Cu surface, and better adhesion on Cu as well as OSG intermetal dielectric (IMD), though the alpha-SiC film has a very slow deposition rate. We believe that the alpha-SiCN/alpha-SiC bilayer dielectric is a favorable combination for the ESL because alpha-SiCN can protect alpha-SiC from plasma attack during the photoresist stripping.
TDDB reliability improvement of Cu damascene with a bilayer-structured alpha-SiC : H dielectric barrier
(2004-02-01)
Chiang, CC
;
Chen, MC
;
Wu, ZC
;
Li, LJ
;
Jang, SM
This work investigates the thermal stability and physical and barrier characteristics of two species of amorphous silicon carbide dielectric films: the nitrogen-containing alpha-SiCN film with a dielectric constant of 4.9 and the nitrogen-free alpha-SiC film with a dielectric constant of 3.8. The time-dependent-dielectric-breakdown (TDDB) lifetime of the Cu damascene metallization structure is greatly improved by using an alpha-SiCN/alpha-SiC bilayer dielectric stack as the barrier layer. This improvement is attributed to the lower leakage current of alpha-SiC, absence of nitridation on the Cu surface, and better adhesion of alpha-SiC on Cu and organosilicate glass intermetal dielectric. Although the alpha-SiC film has a very low deposition rate, the alpha-SiCN/alpha-SiC bilayer dielectric is a favorable combination for the barrier layer because alpha-SiCN can protect alpha-SiC from plasma attack, such as O-2 plasma attack during photoresist stripping and organosilicate plasma attack during organosilicate glass deposition. (C) 2004 The Electrochemical Society.