United Microelectronics Corp.

Powerchip Semiconductor Corporation

Chih-Cheng Liu

Chin-Hui Lee

De-Yuan Wu

Chien-Hua Tsai

Ting-Chi Lin

Der-Yuan Wu

A method of operating a P-channel memory is described. The P-channel memory includes a substrate, a gate formed over the substrate, a charge trapping structure disposed between the substrate and the gate, and the first and second sources/drains formed in the substrate adjacent to two sides of the charge trapping structure. An erasing operation is performed by applying a first voltage to the second source/drain, applying a second voltage to the first source/drain, applying a third voltage to the gate, and applying a forth voltage to the substrate. Hot holes are injected in the charge trapping structure to erase the P-channel memory by the tertiary hot hole mechanism. The absolute value of the voltage differential between the third and the forth voltages is equal to, or less than 6V, and the second voltage is smaller than the third voltage.

Method of operating p-channel memory

A memory module stores digital data. The memory module has many memory cells biased by a voltage source. Each memory cell has an access transistor electrically connected to a word line and a bit line for receiving bits from the bit line when the word line turns on the access transistor, a switching circuit electrically connected to the access transistor, and a capacitor electrically connected to the switching circuit. The switching circuit turns on or off according to the bit from the access transistor. The capacitor stores charge supplied by the switching circuit when the switching circuit turns on. The capacitor stores charge supplied by the voltage source when the switching circuit turns off. When the access transistor turns off, the switching circuit or the voltage source provides charge to the capacitor to sustain the voltage level of the capacitor to compensate for charge leakage of the capacitor.

Memory module having a two-transistor memory cell

A SOI DRAM unit comprising a MOS transistor and an improved SOI substrate having a back-gate control. The SOI substrate includes a first insulating layer, a first semiconductor layer having a first conductivity type, a second insulating layer, and a second semiconductor layer having a first conductivity type formed on a substrate. The MOS transistor includes a gate formed on the second semiconductor layer and a source and drain region, having a second conductivity type, formed on either side of the gate in the second semiconductor layer, wherein the source and the drain electrically connects to a bit line and a capacitor, respectively. A first oxidation region is formed in the first semiconductor layer below the source region and a second oxidation region is formed in the first semiconductor layer below the drain region. Both the first oxidation and second oxidation regions are contiguous with the second insulating layer.

SOI device and method of fabrication

The array includes: a plurality of pseudo spin valve (PSV) cells; a plurality of parallel bit lines, wherein a plurality of bit lines are straight lines and located under the plurality of pseudo spin valve (PSV) cells; a plurality of parallel word lines, wherein a plurality of word lines are continuous-bended lines having a first straight line, a second straight line and a third straight line. These straight lines of the word lines are orthogonal each other, wherein the first straight line and the third straight line are parallel. The first straight line and the third straight line are individually orthogonal with the direction of the bit lines. Furthermore, the second straight lines of the word lines are individually located on the pseudo spin valve (PSV) cells, and the second straight lines are parallel with the direction of the bit lines, so as to increase the magnetresistance ratio.

Array for forming magnetoresistive random access memory with pseudo spin valve

A method of fabricating a buried vertical split gate memory cell is disclosed. First, a first trench is created in an SOI substrate for accommodating a floating gate. A second trench, having a smaller width than that of the first trench, is then created at the bottom of the first trench for accommodating a word line/control gate. Simultaneously, a silicon sidewall step structure is produced and functions as a vertical channel of the buried vertical split gate memory cell, wherein the vertical control gate channel length (L,) and the floating gate channel length (L,) is 0.25 micrometers and about 3.5 nm, respectively.

Method for fabricating a buried vertical split gate memory device with high coupling ratio

The present invention relates to a method of forming a level silicon oxide layer on a semiconductor wafer. The semiconductor wafer comprises a substrate having a first region containing no silicon nitride on its surface and a second region which is higher than the first region and contains a silicon nitride layer on its surface. The method comprises performing a cleaning process on the semiconductor wafer with an alkaline solution to uniform the deposition rate over the surface of the first region; and performing a deposition process employing ozone as a reactive gas with a flow capacity of 80-200 g/L to form a silicon oxide layer above the first and second regions wherein the deposition rate of the silicon oxide layer on the first region is higher than that on the second region and the silicon oxide layer above the first region is leveled with that above the second region after a predetermined period of time.

Method of forming a level silicon oxide layer on two regions of different heights on a semiconductor wafer

The invention relates to an ion implantation method for adjusting the threshold voltage of MOS transistors. The MOS transistor is employed in a DRAM (dynamic random access memory) memory cell in a semiconductor wafer and comprises a substrate, a gate insulating layer positioned on the substrate, and a gate conducting layer with a rectangular-shaped cross section positioned on the gate insulating layer. The method comprises performing an ion implantation process at a predetermined dosage and ion energy to implant dopants through the gate conducting layer and gate insulating layer and deposit the dopants into the superficial portion of the substrate below the gate insulating layer.

Method of ion implantation for adjusting the threshold voltage of MOS transistors

The present invention provides a method of depositing a silicon oxide layer on a semiconductor wafer. The semiconductor wafer comprises a plurality of transistors positioned on its surface. The method comprises performing a cleaning process on the semiconductor wafer by using an alkaline solution to make a more uniform deposition rate of the silicon oxide layer on the transistors and other areas over the surface of the semiconductor wafer, then performing a deposition process by employing ozone as a reactive gas to form a silicon oxide layer of even thickness and without voids.

Method of depositing a silicon oxide layer on a semiconductor wafer

The present invention provides a method of forming a contact hole in a semiconductor wafer. The semiconductor wafer comprises a silicon substrate, a silicon--oxygen layer positioned on the silicon substrate, and a photoresist layer positioned on the silicon--oxygen layer. An anisotropic dry-etching process is performed to vertically remove the silicon--oxygen layer below the opening to a predetermined depth to form the contact hole which contains a polymer layer on its surface. A soft-etching process is performed to remove the polymer layer in the contact hole. The dry-etching process and soft-etching process are performed alternatively to vertically remove the silicon--oxygen layer under the contact hole until the surface of the silicon substrate can be reached through the contact hole.

Growing community of inventors

Taipei, Taiwan

Chih-Cheng Liu