Tower Semiconductor Ltd.

Avi Ben-Gigi

Yakov Roizin

Efraim Aloni

Micha Gutman

Menachem Vofsy

Koji Yoshida

Masatoshi Arai

Fumihiko Noro

Nobuyoshi Takahashi

A pre-metal dielectric structure of a SONOS memory structure includes a UV light-absorbing film, which prevents the ONO structure from being electronically charged in response to UV irradiation. In one embodiment, the pre-metal dielectric structure includes a first pre-metal dielectric layer located over the SONOS memory structure, a light-absorbing structure located over the first pre-metal dielectric layer, and a second pre-metal dielectric layer located over the light-absorbing structure. The light-absorbing structure can be a continuous polysilicon or amorphous silicon layer. Alternately, the light-absorbing structure can include one or more patterned polysilicon layers. In another embodiment, the SONOS transistors include UV light absorbing polysilicon spacers.

Protection against in-process charging in silicon-oxide-nitride-oxide-silicon (SONOS) memories

A fieldless array includes a semiconductor substrate, a plurality of oxide-nitride-oxide (ONO) structures formed over the upper surface of the semiconductor substrate, and a plurality of word lines formed over the ONO structures, wherein each of the ONO structures is substantially covered by one of the word lines. The word lines (typically polysilicon) block UV irradiation during subsequent processing steps, thereby substantially preventing electrons from being trapped in the silicon nitride layer of the ONO structure. As a result, the threshold voltages of the fieldless array transistors do not severely increase as the width of the fieldless array transistors decrease.

Method of decreasing charging effects in oxide-nitride-oxide (ONO) memory arrays

Growing community of inventors

Migdal Haemek, Israel

Avi Ben-Gigi