The invention discloses a radio-frequency LDMOS (Laterally Diffused Metal Oxide Semiconductor) device. A drift region is in a nonuniform structure formed by a first ion injection region and a second ion injection region; the first ion injection region is self-aligned to a polysilicon gate; the second ion injection region is defined by photoetching and is at a distance from the polysilicon gate; a crossover region of the first ion injection region and the second ion injection region has higher doping concentration which can improve driving current of the device and reduce switch-on resistance of the device; the lower doping concentration of the first ion injection region can reduce the intensity of an electric field on the edge of the polysilicon gate, improve breakdown voltage of the device, reduce injection capacity of a hot carrier on the edge of the polysilicon gate and improve robustness of the device; and the lower doping concentration and great depth of the second ion injection region can reduce output capacitance of the device. The invention further discloses a manufacturing method of the radio-frequency LDMOS device.

Radio frequency LDMOS (laterally diffused metal oxide semiconductor) device and manufacture method thereof

A device includes a semiconductor substrate having a surface with a trench, first and second conduction terminals supported by the semiconductor substrate, a control electrode supported by the semiconductor substrate between the first and second conduction terminals and configured to control flow of charge carriers during operation between the first and second conduction terminals, and a Faraday shield supported by the semiconductor substrate and disposed between the control electrode and the second conduction terminal. At least a portion of the Faraday shield is disposed in the trench.

Trenched Faraday shielding

A method of fabricating a P-type surface-channel laterally diffused metal oxide semiconductor device includes forming a gate structure with polysilicon and metal silicide, and the processes of channel implantation, long-time high-temperature drive-in, formation of a heavily doped N-type polysilicon sinker and boron doping of a polysilicon gate, are performed in this order, thereby ensuring the gate not to be doped with boron during its formation. The high-temperature drive-in process is allowed to be carried out to form a channel with a desired width, and a short channel effect which may cause penetration or electric leakage of the resulting device is prevented. As the polysilicon gate is not processed by any high-temperature drive-in process after it is doped with boron, the penetration of boron through a gate oxide layer and the diffusion of N-type impurity contained in the heavily doped polysilicon sinker into the channel or other regions are prevented.

Method of fabricating P-type surface-channel LDMOS device with improved in-plane uniformity

A laterally diffused metal oxide semiconductor (LDMOS) transistor structure with improved unclamped inductive switching immunity. The LDMOS includes a substrate and an adjacent epitaxial layer both of a first conductivity type. A gate structure is above the epitaxial layer. A drain region and a source region, both of a second conductivity type, are within the epitaxial layer. A channel is formed between the source and drain region and arranged below the gate structure. A body structure of the first conductivity type is at least partially formed under the gate structure and extends laterally under the source region, wherein the epitaxial layer is less doped than the body structure. A conductive trench-like feed-through element passes through the epitaxial layer and contacts the substrate and the source region. The LDMOS includes a tub region of the first conductivity type formed under the source region, and adjacent laterally to and in contact with said body structure and said trench-like feed-through element.

Transistor structure with improved unclamped inductive switching immunity

Approaches for LDMOS devices are provided. A method of forming a semiconductor structure includes forming a gate dielectric including a first portion having a first uniform thickness, a second portion having a second uniform thickness different than the first uniform thickness, and a transition portion having tapered surface extending from the first portion to the second portion. The gate dielectric is formed on a planar upper surface of a substrate. The tapered surface is at an acute angle relative to the upper surface of the substrate.

Tapered gate oxide in ldmos devices

The invention discloses a radio frequency (RF) laterally diffused metal oxide semiconductor (LDMOS) component Based on a component structure using tungsten-subsidence electric connection, a middle doped P type buried layer is arranged in a P type heave doped region on one side on a source end channel in an ion injection mode after an ion injection process and a thermal propelling process in a channel and a light dope diffusion drift region The P type buried layer can reduce base electrode resistance of a parasitic non-protein nitrogen (NPN) pipe, so that snapback effect is not prone to generate A reversed diode formed by a source electrode, the channel and the buried layer can strangulate drain-source voltage of an LDMOS and can sink extra current on a substrate The invention further discloses a manufacture method for the RF LDMOS component In the process realization, the manufacture method only adds one step of ion injection based on an existing process so as to be easy to implement

Radio frequency (RF) laterally diffused metal oxide semiconductor (LDMOS) component and manufacture method

A radio frequency (RF) laterally diffused metal oxide semiconductor (LDMOS) device is disclosed which additionally includes a lightly-doped P-type buried layer under a P-type channel region and a moderately-dope P-type buried layer in the lightly-doped P-type buried layer. The two buried layers result in a lower base resistance for an equivalent parasitic NPN transistor, thereby impeding the occurrence of snapback in the device. Additionally, an equivalent reverse-biased diode formed between the channel region and the buried layers is capable of clamping the drain-source voltage of the device and sinking redundant currents to a substrate thereof. Furthermore, the design of a gate oxide layer of the RF LDMOS device to have a greater thickness at a proximal end to a drain region can help to reduce the hot-carrier effect, and having a smaller thickness at a proximal end to the source region can improve the transconductance of the RF LDMOS device.

Rf ldmos device and fabrication method thereof

The invention discloses an electric connection structure for a connection trap and a substrate in a radio frequency (RF) laterally diffused metal oxide semiconductor (LDMOS) and a manufacture method. A P type epitaxy is grown on a P type substrate, a silicon oxide thermal oxidation layer is grown, a silicon nitride layer is deposited on the silicon oxide thermal oxidation layer, a field oxygen opening can be formed through photoetching and etching, a silicon oxide blocking layer is deposited, the silicon oxide blocking layer at the position of the field oxygen opening can be opened by photoetching and etching, the P type epitaxy is etched to the substrate to form a groove, the silicon oxide layer is removed through a wet method to grow field oxygen, field oxygen in the groove is removed by photoetching and wet method etching to carry out small-angle large-dose P type ion injection, non-doped polycrystalline silicon is deposited, polycrystalline silicon on the silicon nitride layer is etched again to be removed, thermal oxidation is carried out again, a thermal oxidation layer on the groove is removed through photoetching and wet method etching, P type ions are vertically injected into the polycrystalline silicon, and thermal expansion is carried out to enable injected ions to diffuse. The electric connection structure reduces resistance, can completely meet the requirement that the ground connection end of a metal oxide semiconductor (MOS) pipe is led out from the back of a silicon wafer, and reduces effects of high inductance on radio frequency performance caused by a ground connection metal connection line.

Electric connection structure for connection trap and substrate in radio frequency (RF) laterally diffused metal oxide semiconductor (LDMOS) and manufacture method

The invention discloses a radio frequency LOMOS device for overcoming electricity leakage A silicide barrier layer is arranged on a gate oxide layer, and a shielding ring barrier layer is arranged on the silicide barrier layer A leading-out terminal adhesion layer is arranged on a drain electrode, and a drain electrode leading-out terminal is arranged on the leading-out terminal adhesion layer A shielding ring adhesion layer is arranged on a shielding ring dielectric layer, and a metal Faraday shielding ring is arranged on the shielding ring adhesion layer The leading-out terminal adhesion layer and the shielding ring adhesion layer are made of same polycrystalline silicon or titanium materials The drain electrode leading-out terminal and the metal Faraday shielding ring are made of same metal or metal silicide materials The invention further discloses a manufacturing method of the radio frequency LOMOS device By means of the radio frequency LOMOS device and the manufacturing method, lesser electricity can be leaked, the shielding effect can be strengthened, and the product reliability is improved

Radio frequency LOMOS device for overcoming electricity leakage and manufacturing method of radio frequency LOMOS device for overcoming electricity leakage

Here is presented an optimized RF-LDMOS (Radio Frequency Lateral Double Diffused MOS) structure with double grounded G-shield and multiple drift region implants which significantly improved HCI and high RF performance especially for high frequency application. The experimental data shown both excellent HCI and high RF performance have been achieved. Measured with full load test, we have gained 1.42 W/mm and 1.36 W/mm output power density and 68.76% and 65.97% drain efficiency in 2110MHz and 2600MHz respectively. And the I dq and R dson degradation are both less than 5% when extrapolate to 20 years.

Cai Ying

Papers

Radio frequency (RF) laterally diffused metal oxide semiconductor (LDMOS) component and manufacture method

Rf ldmos device and fabrication method thereof

Electric connection structure for connection trap and substrate in radio frequency (RF) laterally diffused metal oxide semiconductor (LDMOS) and manufacture method

Radio frequency LOMOS device for overcoming electricity leakage and manufacturing method of radio frequency LOMOS device for overcoming electricity leakage

Optimization of RF performance and reliability of 28V RF-LDMOS