Method for forming nitride read only memory
AssigneeMacronix International Co., Ltd.
InventorsSamuel Pan, Chia-Hsing Chen, Chun-Jung Lin, Minnie Hsiung
Life of this patent
Estimating the term…
Abstract
First of all, a semiconductor substrate having a source/drain region is provided, wherein a channel being formed in the space between the source/drain region within the semiconductor substrate. Then the oxide-nitride-oxide layers are formed on the semiconductor substrate, wherein the nitride layer is a charge trapping layer. Afterward, an electrically conductive material layer as a gate is formed on and overlaying the oxide-nitride-oxide layers. Subsequently, the memory cell is programmed by ultraviolet light irradiation to increase threshold voltage of the memory cell.
Claims22
A method for programming a memory, the method comprising:
- providing a semiconductor substrate having a source/drain region therein, wherein said source/drain region is separated at a predetermined region for programming from each other;
- forming a dielectric layer on said semiconductor substrate;
- forming a conductive layer on said dielectric layer;
- forming and defining a photoresist layer on said conductive layer that is located on source/drain region to expose a partial surface of said conductive layer that is located on said predetermined region for programming;
- irradiating said predetermined region for programming with a light having an energy for activating electrons by said photoresist layer as a mask to program said memory;
- and
- removing said photoresist layer on said conductive layer.
A method for programming a read only memory, the method comprising:
- providing a semiconductor substrate having a source/drain region therein, wherein said source/drain region is separated at a channel from each other;
- forming a first isolated layer on said semiconductor substrate;
- forming a charge strapping layer on said first isolated layer;
- forming a second isolated layer on said charge strapping layer;
- forming a conductive layer on said second isolated layer;
- forming and defining a photoresist layer on said conductive layer that is located on source/drain region to expose a partial surface of said conductive layer that is located on said channel;
- irradiating said channel with a light having an energy about 3 eV to 9 eV for activating electrons by said photoresist layer as a mask to program said read only memory;
- and
- removing said photoresist layer on said conductive layer.
A method for programming a nitride read only memory, the method comprising:
- providing a semiconductor substrate having a first conductivity;
- forming a plurality of source/drain regions having a second conductivity in said semiconductor substrate, wherein said plurality of source/drain regions are separated at a plurality of channels from each other;
- depositing a first oxide layer on said semiconductor substrate to form a first isolated layer;
- depositing a nitride layer on said first oxide layer to form a charge strapping layer;
- depositing a second oxide layer on said nitride layer to form a second isolated layer;
- depositing a polysilicon layer on said second oxide layer to form a conductive layer;
- defining a plurality of photoresist layers on said polysilicon layer that are located on said plurality of source/drain regions and exposing a portion surface of said polysilicon layer that are located on said plurality of channels to form a plurality of predetermined regions for programming;
- irradiating said plurality of predetermined regions for programming with an ultraviolet light by said plurality of photoresist layers as masks to program said nitride read only memory;
- and
- removing said plurality of photoresist layers on said polysilicon layer to form said nitride read only memory.
Dependencies are inferred from the claim text.