Etron Technology, Inc.

Industrial Technology Research Institute

Kun-Zen Chang

Nicky C Lu

Ching-Yuan Lin

Ming-Zen Lin

Rong-Tai Kao

Deng-Shun Chang

Jyh-Chyurn Guo

In this invention a deep N-type wall is created surrounding an area that contains an ESD device, or circuit. The ESD device, or circuit, is connected to a chip pad and is first surrounded by a P&plus; guard ring. The P&plus; guard ring is then surrounded by the deep N-type wall to block excess current from an ESD event or voltage overshoot from reaching the internal circuitry. The deep N-type wall comprises an N&plus; diffusion within an N-well which is on top of a deep N-well. The height of the deep N-type wall is approximately 4 to 6 micrometers which provides a capability to absorb much of the current from an ESD event or voltage overshoot.

Guard ring structure with deep N well on ESD devices

A DRAM device having improved performance of peripheral circuitry is described. The performance is improved by selectively having MOS transistors with a thinner gate oxide in peripheral circuits having a lower voltage applied to their gate electrodes. The DRAM device will maintain reliability by having MOS transistors with a thicker gate oxide in the memory cells and selected peripheral circuitry that are subjected to a higher voltage at their gate electrodes. Further this invention describes methods of fabricating the DRAM device with selectively placed multiple gate oxide thickness.

High performance DRAM structure employing multiple thickness gate oxide

A method for forming an ESD protection device, with reduced junction breakdown voltages, while simultaneously forming an integrated circuit, containing FET devices, has been developed. This invention features forming a large area, ESD protection diode, by using a first ion implantation step, of a specific conductivity type, also used for the heavily doped source and drain regions of attached FET devices. After photoresist processing, used to mask the attached FET devices, a second ion implantation step, opposite in conductivity type then the first implant, is used to complete the ESD protection diode, for the ESD protection device. This large area diode reduces junction breakdown voltage, while allowing ESD current to be discharged more efficiently then for smaller ESD protection counterparts.

Protection device structure for low supply voltage applications

Method of making ESD protection device structure for low supply voltage

An improved field effect transistor having a source region, a drain region, and channel region in a polycrystalline silicon layer, the improvement being that the polycrystalline silicon layer has approximately equal concentrations of N and P type dopants embodied therein, which serves to restrain movement of P/N junctions.

Polycrystalline silicon thin film transistor

A double polysilicon dual gate LDMOSFET structure combined with a detecting circuit can be used to reduce the ON state resistance and without degradation of the breakdown voltage of the LDMOSFET. In the ON state, a drift region is driven into accumulation. In the OFF state, a gate is made to float and thereby avoid degradation of the breakdown voltage. A switch or transistor is modulated to either allow applied voltage to bias the gate for enabling the drift region to be driven into accumulation or to cause the gate to float to prevent the driving of the drift region by the voltage.

Dual gate LDMOSFET device for reducing on state resistance

A process of fabricating an improved transistor on a polycrystalline silicon layer, wherein N and P type dopants, in approximate equal concentrations, are introduced into the layer, and the layer heated. The resultant modified polycrystalline silicon layer inhibits the migration of dopants, used to form the active regions of the device, during subsequent heating steps. An improved field effect transistor having a source region, a drain region, and channel region in a polycrystalline silicon layer, the improvement being that the polycrystalline silicon layer has approximately equal concentrations of N and P type dopants embodied therein, which serves to restrain movement of P/N junctions.

Growing community of inventors

Hsinchu, Taiwan

Kun-Zen Chang