摘要:
The present invention gives a method for creating a NROM memory from a semiconductor substrate. Numerous process steps are included to achieve this including forming shallow trench isolation areas, many ion implantation processes, ROM code implantation processes, photolithography and creation of layers and removal of layers. At the end of the process a mixed-signal circuit embedded NROM and NROM memory are created.
摘要:
A method of forming an embedded memory integrating nitride read only memory starts by forming an ONO layer and a protective cap layer on a surface of a semiconductor substrate defined with a memory area and a periphery area. The periphery area has a first, a second and a third device area. An etching and a first ion implantation process form each bit line in the memory area. A spacer is then formed at either side of the protective cap layer and the ONO layer in the memory area, and the protective cap layer and the ONO layer are removed in the first device area. The threshold voltage for the first device area is adjusted and a first thermal oxidation process forms a buried drain oxide layer atop each bit line and a first gate oxide layer on the surface of the first device area, respectively. The protective cap layer and the ONO layer are removed from the second device area and the third device area, and a second gate oxide layer is formed in the second device area and the third device area. Finally, the protective cap layer in the memory area and the second gate oxide layer in the third device area are removed, and a third gate oxide layer is formed in the third device area.
摘要:
A method of simultaneously forming a dual damascence runner and a metal-insulator-metal (MIM) capacitor on a semiconductor wafer. The semiconductor wafer has a first dielectric layer, which has at least a first conductive layer and at least a bottom electrode of the MIM capacitor. The surfaces of the first conductive layer and the bottom electrode of the MIM capacitor are covered with a barrier layer. A second dielectric layer, a stop layer and a third dielectric layer are formed on the surface of the barrier layer and form a sandwiched structure. A first photoresist layer is formed and the third dielectric layer is anisotropically etched down to the stop layer, thus forming a trench and an opening in the third dielectric layer above the conductive layer and the bottom electrode of the MIM capacitor. A second photoresist layer is formed and the stop layer and the second dielectric layer are etched at a bottom of the opening down to the surface of the barrier layer so as to form an opening of the top electrode. A third photoresist layer is formed and the stop layer, the second dielectric layer and the barrier layer are etched through the contact opening down to the surface of the first conductive layer so as to form a contact hole.
摘要:
A method of forming an NROM comprising mixed-signal circuits is provided. The method starts by providing a semiconductor substrate having a memory area and a periphery area. The periphery area has a plurality of active areas isolated by an isolation layer. A bottom electrode of a capacitor is formed atop the isolation layer in the periphery area. An ONO(oxide-nitride-oxide) process is performed. A photolithography, an anisotropic etching, and an ion implantation process are performed in order to etch the ONO dielectric layer in a bit line region not protected by the first photolithography process, and to form a plurality of buried bit lines. A photolithography and an ion implantation process are performed in order to form at least one ion well. The surface of the active area in the periphery area is wet etched. An oxidation process is performed in order to simultaneously form at least one gate oxide layer with a specific thickness in the active area, and to form a thermal oxide layer atop each of the buried bit lines in the memory area. Each of the gates, the top electrode of the capacitor and the resistor are formed in the periphery area, and a word line is formed in the memory area.
摘要:
An ONO dielectric layer is formed on the surface of a substrate, and then a plurality of bit lines are formed in the substrate by utilizing a photolithography and an ion implantation process. Thereafter the ONO dielectric layer in the periphery area is removed and the threshold voltage of the periphery transistor is adjusted. After the ONO dielectric layer in the read only memory area is removed, and a buried drain oxide layer and a plurality of gate oxide layers are formed atop each bit line and the surface of each device respectively. Then each word line in the memory area and each gate of each periphery transistor in the periphery area is formed so as to simultaneously form at least a nitride read only memory in the nitride read only memory area and a high, low threshold voltage device in the read only memory area. Finally the threshold voltage of the high threshold voltage device is adjusted by utilizing a ROM code implantation process.
摘要:
The present invention provides a method utilizing the fabrication process of poly-Si spacers to build a flash memory with 2bit/cell. In the present invention, recessed poly-Si spacers are used to fabricate discontinuous floating gates below a control gate to build a flash memory with 2bit/cell. The present invention is characterized in that the fabrication process of poly-Si spacers is exploited to complete the fabrication process of floating gates in automatic alignment way without any extra mask process. Moreover, each memory cell in this flash memory can store two bits, hence increasing the memory capacity.
摘要:
The present invention discloses a method of utilizing the fabrication process of floating gate spacer to build a twin-bit MONOS/SONOS memory, wherein recessed ONO spacers are used to fabricate a discontinuous floating gate below a poly control gate to obtain a MONOS/SONOS memory device having twinbit memory cells. Cross talk between charges stored in the two bits can be avoided, hence enhancing the reliability of memory device. Moreover, if the voltage Vt varies during the fabrication process, the device can restore its normal characteristics through the individual and separate characteristic of the two bits and by using program or erase condition. The present invention can utilize the fabrication process of ONO spacer to complete the fabrication process of floating gate in automatic alignment way without the need of undergoing several mask processes.
摘要:
A method for forming an integrated circuit having metal-oxide nitride-oxide semiconductor (MONOS) memories and mixed-signal circuits is disclosed. The invention integrates non-volatile memory devices such as MONOS devices and logic devices such as MOS devices as well as PIP capacitors into SOC devices with reduced process steps.
摘要:
This invention relates to a method for forming the salicide, more particularly, to the method for forming the salicide in the partial region. The present invention uses an oxide layer to be the mask layer to form the salicide in the partial region of the logic circuit. The silicide is formed on the gate and is not formed in the diffusion region, which are in the cell array region. The silicide is formed on the gate and in the diffusion region, which are in the periphery region. The present invention method can make the semiconductor device obtain lower resistance and decrease the leakage defects.
摘要:
The present invention mainly provides a method to locally form metal silicide on an integral circuit and to avoid the phenomenon of leakage current which is caused by metal silicide formed between the memory cells on the same word line. The method of present invention achieve above objectives by principally using a design rule to adequately arrange elements in proper distance. In an embodiment, in order to form metal silicide layers on an integral circuit and to avoid metal silicide formed between two neighboring memory cell on the same word line, a dielectric layer is previously formed in the spaced region between the two neighboring memory cells and is used as a mask. Thus, in a following selective etching process, a part of silicon substrate within the above spaced region can be protected and not exposed. Therefore, no metal silicide is formed in the spaced region, and the above objectives is achieved.