Highly Reliable Flash Memories Fabricated by <I>in</I>-<I>situ</I> Multiple Rapid Thermal Processing

Takahisa HAYASHI; Yoshiyuki KAWAZU; Akira UCHIYAMA; Hisashi FUKUDA

Highly Reliable Flash Memories Fabricated by in-situ Multiple Rapid Thermal Processing

Takahisa HAYASHI, Yoshiyuki KAWAZU, Akira UCHIYAMA, Hisashi FUKUDA

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We propose, for the first time, highly reliable flash-type EEPROM cell fabrication using in-situ multiple rapid thermal processing (RTP) technology. In this study, rapid thermal oxynitridation tunnel oxide (RTONO) film formations followed by in-situ arsenic (As)-doped floating-gate polysilicon growth by rapid thermal chemical vapor deposition (RTCVD) technologies are fully utilized. The results show that after 510⁴ program/erase (P/E) endurance cycles, the conventional cell shows 65% narrowing of the threshold voltage (V_t) window, whereas the RTONO cell indicates narrowing of less than 20%. A large number of nitrogen atoms (10²⁰ atoms/cm³) are confirmed by secondary ion mass spectrometry (SIMS), pile up at the SiO₂/Si interface and distribute into bulk SiO₂. It is considered that in the RTONO film stable Si-N bonds are formed which minimize electron trap generation as well as the neutral defect density, resulting in lower V_t shifts in P/E stress. In addition, the RTONO film reduces the number of hydrogen atoms because of final N₂O oxynitridation. The SIMS data shows that by the in-situ RTCVD process As atoms (910²⁰ atoms/cm³) are incorporated uniformly into 1000--thick film. Moreover, the RTCVD polysilicon film indicates an extremely flat surface. The time-dependent dielectric breakdown (TDDB) characteristics of interpoly oxide-nitride-oxide (ONO) film exhibited no defect-related breakdown and 5 times longer breakdown time as compared to phosphorus-doped polysilicon film. Therefore, the flash-EEPROM cell fabricated has good charge storing capability.

Publication: IEICE TRANSACTIONS on Electronics Vol.E77-C No.8 pp.1270-1278

Publication Date: 1994/08/25

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Type of Manuscript: Special Section PAPER (Special Section on High Speed and High Density Multi Functional LSI Memories)

Category: Non-volatile Memory

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Takahisa HAYASHI, Yoshiyuki KAWAZU, Akira UCHIYAMA, Hisashi FUKUDA, "Highly Reliable Flash Memories Fabricated by in-situ Multiple Rapid Thermal Processing" in IEICE TRANSACTIONS on Electronics, vol. E77-C, no. 8, pp. 1270-1278, August 1994, doi: .
Abstract: We propose, for the first time, highly reliable flash-type EEPROM cell fabrication using in-situ multiple rapid thermal processing (RTP) technology. In this study, rapid thermal oxynitridation tunnel oxide (RTONO) film formations followed by in-situ arsenic (As)-doped floating-gate polysilicon growth by rapid thermal chemical vapor deposition (RTCVD) technologies are fully utilized. The results show that after 510⁴ program/erase (P/E) endurance cycles, the conventional cell shows 65% narrowing of the threshold voltage (V_t) window, whereas the RTONO cell indicates narrowing of less than 20%. A large number of nitrogen atoms (10²⁰ atoms/cm³) are confirmed by secondary ion mass spectrometry (SIMS), pile up at the SiO₂/Si interface and distribute into bulk SiO₂. It is considered that in the RTONO film stable Si-N bonds are formed which minimize electron trap generation as well as the neutral defect density, resulting in lower V_t shifts in P/E stress. In addition, the RTONO film reduces the number of hydrogen atoms because of final N₂O oxynitridation. The SIMS data shows that by the in-situ RTCVD process As atoms (910²⁰ atoms/cm³) are incorporated uniformly into 1000--thick film. Moreover, the RTCVD polysilicon film indicates an extremely flat surface. The time-dependent dielectric breakdown (TDDB) characteristics of interpoly oxide-nitride-oxide (ONO) film exhibited no defect-related breakdown and 5 times longer breakdown time as compared to phosphorus-doped polysilicon film. Therefore, the flash-EEPROM cell fabricated has good charge storing capability.
URL: https://global.ieice.org/en_transactions/electronics/10.1587/e77-c_8_1270/_p

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@ARTICLE{e77-c_8_1270,
author={Takahisa HAYASHI, Yoshiyuki KAWAZU, Akira UCHIYAMA, Hisashi FUKUDA, },
journal={IEICE TRANSACTIONS on Electronics},
title={Highly Reliable Flash Memories Fabricated by in-situ Multiple Rapid Thermal Processing},
year={1994},
volume={E77-C},
number={8},
pages={1270-1278},
abstract={We propose, for the first time, highly reliable flash-type EEPROM cell fabrication using in-situ multiple rapid thermal processing (RTP) technology. In this study, rapid thermal oxynitridation tunnel oxide (RTONO) film formations followed by in-situ arsenic (As)-doped floating-gate polysilicon growth by rapid thermal chemical vapor deposition (RTCVD) technologies are fully utilized. The results show that after 510⁴ program/erase (P/E) endurance cycles, the conventional cell shows 65% narrowing of the threshold voltage (V_t) window, whereas the RTONO cell indicates narrowing of less than 20%. A large number of nitrogen atoms (10²⁰ atoms/cm³) are confirmed by secondary ion mass spectrometry (SIMS), pile up at the SiO₂/Si interface and distribute into bulk SiO₂. It is considered that in the RTONO film stable Si-N bonds are formed which minimize electron trap generation as well as the neutral defect density, resulting in lower V_t shifts in P/E stress. In addition, the RTONO film reduces the number of hydrogen atoms because of final N₂O oxynitridation. The SIMS data shows that by the in-situ RTCVD process As atoms (910²⁰ atoms/cm³) are incorporated uniformly into 1000--thick film. Moreover, the RTCVD polysilicon film indicates an extremely flat surface. The time-dependent dielectric breakdown (TDDB) characteristics of interpoly oxide-nitride-oxide (ONO) film exhibited no defect-related breakdown and 5 times longer breakdown time as compared to phosphorus-doped polysilicon film. Therefore, the flash-EEPROM cell fabricated has good charge storing capability.},
keywords={},
doi={},
ISSN={},
month={August},}

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TY - JOUR
TI - Highly Reliable Flash Memories Fabricated by in-situ Multiple Rapid Thermal Processing
T2 - IEICE TRANSACTIONS on Electronics
SP - 1270
EP - 1278
AU - Takahisa HAYASHI
AU - Yoshiyuki KAWAZU
AU - Akira UCHIYAMA
AU - Hisashi FUKUDA
PY - 1994
DO -
JO - IEICE TRANSACTIONS on Electronics
SN -
VL - E77-C
IS - 8
JA - IEICE TRANSACTIONS on Electronics
Y1 - August 1994
AB - We propose, for the first time, highly reliable flash-type EEPROM cell fabrication using in-situ multiple rapid thermal processing (RTP) technology. In this study, rapid thermal oxynitridation tunnel oxide (RTONO) film formations followed by in-situ arsenic (As)-doped floating-gate polysilicon growth by rapid thermal chemical vapor deposition (RTCVD) technologies are fully utilized. The results show that after 510⁴ program/erase (P/E) endurance cycles, the conventional cell shows 65% narrowing of the threshold voltage (V_t) window, whereas the RTONO cell indicates narrowing of less than 20%. A large number of nitrogen atoms (10²⁰ atoms/cm³) are confirmed by secondary ion mass spectrometry (SIMS), pile up at the SiO₂/Si interface and distribute into bulk SiO₂. It is considered that in the RTONO film stable Si-N bonds are formed which minimize electron trap generation as well as the neutral defect density, resulting in lower V_t shifts in P/E stress. In addition, the RTONO film reduces the number of hydrogen atoms because of final N₂O oxynitridation. The SIMS data shows that by the in-situ RTCVD process As atoms (910²⁰ atoms/cm³) are incorporated uniformly into 1000--thick film. Moreover, the RTCVD polysilicon film indicates an extremely flat surface. The time-dependent dielectric breakdown (TDDB) characteristics of interpoly oxide-nitride-oxide (ONO) film exhibited no defect-related breakdown and 5 times longer breakdown time as compared to phosphorus-doped polysilicon film. Therefore, the flash-EEPROM cell fabricated has good charge storing capability.
ER -