Browsing by Author "SU, HP"

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A NEW PORTRAYAL OF OXIDATION OF UNDOPED POLYCRYSTALLINE SILICON FILMS IN A SHORT-DURATION
(1994-01-01)
WANG, PW
;
SU, HP
;
TSAI, MJ
;
HONG, G
;
FENG, MS
Both polysilicon films low-pressure chemical-vapor-deposited (LPCVD) at 625 degrees C and amorphous films deposited at 550 degrees C with subsequent annealing at 600 degrees C for 24 h to form polysilicon films were used to grow polyoxides at 850 degrees C in wet or dry oxygen. Detailed high-resolution transmission electron microscopy (HRTEM) and X-ray diffraction (XRD) studies have been performed to determine the microstructures of the polyoxide/polysilicon interface and the crystallinity of the polysilicon films. It is found that the oxidation phenomena of these two films are very different. For the recrystallized amorphous silicon specimens, the polyoxide/polysilicon interface is very flat because of the poor crystallinity and low-angle grain boundaries between the grains. On the other hand, the polyoxide/polysilicon interface is rough for the as-deposited polysilicon samples due to the distinct grain characteristics and the high-angle grain boundaries between these grains.
ELECTRICAL CHARACTERISTICS OF THIN-FILM TRANSISTORS WITH DOUBLE-ACTIVE-LAYER STRUCTURE
(1995-02-01)
TSAI, MJ
;
WANG, PW
;
SU, HP
;
CHENG, HC
;
電子工程學系及電子研究所
Thin-film transistors (TFTs) with a doubie-active-layer (DAL) structure have been proposed and found to exhibit two kinds of special electrical characteristics. One is the improvement of current drivability and transconductance as compared to the traditional structure. The other is the double-switching characteristics caused by the bi-transistor action. By means of a buried oxide separating the conduction channel into two parts, carrier transport could be enhanced due to the reduction of the vertical electric Field. In addition, the weak avalanche breakdown for the top channel results in hole accumulation in the top poly-Si/buried oxide interface, further promoting the conduction of the bottom active layer, leading to the novel double-switching properties.
HIGH-PERFORMANCE NITRIDED OXIDES FABRICATED BY VERY-LOW-PRESSURE NITRIDATION TECHNIQUE
(1995-04-01)
SU, HP
;
CHENG, HC
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
A never and simple method is proposed to produce high-performance nitrided oxides. Thin oxides nitrided only in NH3 at 900 degrees C for 1 h at 0.1 Torr have excellent interface stability, few electron traps, and excellent reliability. Although the nitrogen concentration [N] at the dielectric/Si substrate interface is kept at a low value, the hydrogen concentration [H] has been shown to be comparable to that of pure oxide at the beginning of the nitridation. Consequently, a high ratio of [N]/[K], which reflects the stable interface, can be attained at the initial stage of the very-low-pressure nitridation (VLPN). This is very different from the case of conventional low-pressure nitridation. The retarded formations of the interfacial Si3N4 and the surface nitrogen-rich oxynitrides are conjectured to be the main cause of reduction in the hydrogen content in the dielectrics during VLPN. Due to the simplicity and wide process window, VLPN is promising for the future ultra-large-scale-integration (ULSI) technology.
HIGH-PERFORMANCE SUPERTHIN OXIDE/NITRIDE/OXIDE STACKED DIELECTRICS FORMED BY LOW-PRESSURE OXIDATION OF ULTRATHIN NITRIDE
(1995-04-01)
LIU, HW
;
SU, HP
;
CHENG, HC
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
High-performance superthin oxide/nitride/oxide (O/N/O) stacked dielectrics have been successfully achieved by oxidizing ultrathin nitride films in low-pressure dry oxygen at 850 degrees C for 30 min. The low leakage current and the high reliability of this O/N/O structure are attributed to the growth of the top oxide on the nitride, which is confirmed by Auger electron spectroscopy (AES) depth profiles and step-by-step diluted-HF etching results. The commonly used Net oxidation of the nitrides at atmospheric pressure cannot attain an effective oxide thickness of as low as 46 Angstrom. Furthermore, the dry oxidation of nitrides at atmospheric pressure can only yield a nitride/oxide (N/O) structure, which results in high leakage current. Therefore: our novel technique is promising for future dynamic-random-access-memory (DRAM) technology.
NOVEL TUNNELING DIELECTRIC PREPARED BY OXIDATION OF ULTRATHIN RUGGED POLYSILICON FOR 5-V-ONLY NONVOLATILE MEMORIES
(1995-06-01)
SU, HP
;
LIU, HW
;
WANG, PW
;
CHENG, PW
;
JEN, IM
A novel dielectric fabricated dy thermal oxidation of ultrathin rugged polysilicon film is proposed for nonvolatile memories, Different roughness degrees for the top and bottom interfaces of this dielectric ate detected by the atomic-force-microscopy (AFM) and high resolution transmission electron microscopy (HRTEM), Due to the microtips formed at the bottom interface of the dielectric, significant improvements in the high conduction efficiency, low trapping rate, good uniformity, and high reliability under positive gate-bias are obtained for the dielectric. Therefore, rugged polyoxide is promising for future 5-V-only floating-gate applications.
SUPERIOR LOW-PRESSURE-OXIDIZED SI3N4 FILMS ON RAPID-THERMAL-NITRIDED POLY-SI FOR HIGH-DENSITY DRAMS
(1995-11-01)
CHANG, HC
;
LIU, HW
;
SU, HP
;
HONG, G
;
奈米中心
High-performance stacked storage capacitors with small effective-oxide-thickness (t(ox),(eff)) as thin as 37 Angstrom has been achieved using low-pressure-oxidized nitride films deposited on NH3-nitrided poly-Si electrodes. The capacitors exhibit excellent leakage property and time-dependent-dielectric-breakdown (TDDB) characteristics. Furthermore, this technique is promising for the 64- and 256-Mb dynamic-random-access-memory (DRAM) applications because the process temperatures never exceed 850 degrees C.
SUPERIOR LOW-PRESSURE-OXIDIZED SI3N4 FILMS ON RAPID-THERMAL-NITRIDED POLY-SI FOR HIGH-DENSITY DRAMS
(1995-11-01)
CHANG, HC
;
LIU, HW
;
SU, HP
;
HONG, G
;
奈米中心
High-performance stacked storage capacitors with small effective-oxide-thickness (t(ox),(eff)) as thin as 37 Angstrom has been achieved using low-pressure-oxidized nitride films deposited on NH3-nitrided poly-Si electrodes. The capacitors exhibit excellent leakage property and time-dependent-dielectric-breakdown (TDDB) characteristics. Furthermore, this technique is promising for the 64- and 256-Mb dynamic-random-access-memory (DRAM) applications because the process temperatures never exceed 850 degrees C.
SUPERTHIN O/N/O STACKED DIELECTRICS FORMED BY OXIDIZING THIN NITRIDES IN LOW-PRESSURE OXYGEN FOR HIGH-DENSITY MEMORY DEVICES
(1994-11-01)
SU, HP
;
LIU, HW
;
HONG, G
;
CHENG, HC
;
電子工程學系及電子研究所
High-performance superthin oxide/nitride/oxide (O/N/O) stacked dielectrics have been successfully achieved by oxidizing thin nitride films in low-pressure dry-oxygen at 850-degrees-C for 30 min. Since the nitrides exhibit a better oxidation resistance to the low-pressure dry-oxygen than to the atmospheric-pressure dry-oxygen and wet-oxygen, the low pressure oxidation obtains a thinner oxidized nitride for the high-density dynamic-random-access-memories (DRAM's) and metal-oxide-nitride-oxide-semiconductor (MONO'S) memory devices. In addition, this dielectric possesses low leakage current and excellent time-dependent-dielectric-breakdown (TDDB) characteristics. Therefore, this novel recipe is promising for future ULSI technology.