Abstract: A phase change memory with a very limited area of contact between the lower electrode and the phase change material may be formed by defining a closed geometric structure for the lower electrode. The lower electrode may then be covered. The covering may then be opened in a very narrow strip extending across the closed geometric shape using phase shift masking. A phase change material may be formed in the opening. Because the opening effectively bisects the closed geometric structure of the lower electrode, two very small contact areas may be created for contacting the lower electrode to the phase change material.

Abstract: A phase change memory with a very limited area of contact between the lower electrode and the phase change material may be formed by defining a closed geometric structure for the lower electrode. The lower electrode may then be covered. The covering may then be opened in a very narrow strip extending across the closed geometric shape using phase shift masking. A phase change material may be formed in the opening. Because the opening effectively bisects the closed geometric structure of the lower electrode, two very small contact areas may be created for contacting the lower electrode to the phase change material.

Abstract: A phase change memory with a very limited area of contact between the lower electrode and the phase change material may be formed by defining a closed geometric structure for the lower electrode. The lower electrode may then be covered. The covering may then be opened in a very narrow strip extending across the closed geometric shape using phase shift masking. A phase change material may be formed in the opening. Because the opening effectively bisects the closed geometric structure of the lower electrode, two very small contact areas may be created for contacting the lower electrode to the phase change material.

Abstract: A method of reducing the degradation effects associated with avalanche injection or tunnelling of hot-electrons in a field-effect semiconductor device is disclosed. The method of the present invention includes covering the active regions of the semiconductor device with a protective titanium barrier layer which is deposited directly underneath the ordinary metalization layers used for connecting the devices to bit and word lines within an array. Inclusion of the titanium barrier layer in a flash memory device results in a substantial improvement in the erasetime push-out and reduces excess charge loss normally associated with hot-electron devices.

Abstract: A method for fabricating floating gate memory arrays with improved electrical erase characteristics and a reduced gate oxide defect density is described. According to the invented method, a protective polysilicon layer is deposited immediately following growth of the tunnel or gate oxide. The polysilicon layer caps the gate oxide--protecting it from exposure to defect-causing contaminants and to insure that a uniform tunnel oxide thickness is maintained across the entire length of the channel; especially over the electron tunneling regions. Following application of the protective polysilicon layer, a second polysilicon layer is deposited and merges with the first polysilicon layer to form the floating gate for the device. Erase speed is improved for flash EEPROM devices fabricated according to the present invention by about 5-100 times.