A bulk finFET with partial dielectric isolation is disclosed. The dielectric isolation is disposed underneath the channel, and essentially bounded by the channel, such that it does not extend laterally beyond the channel under the source and drain regions. This allows increased volume of SiGe source and drain stressor regions placed adjacent to the channel, allowing for a more strained channel, which improves carrier mobility. An N+ doped silicon region is disposed below the dielectric isolation and extends laterally beyond the channel and underneath the stressor source and drain regions, forming a reverse-biased p/n junction with the P+ doped source and drain SiGe stressor to minimize leakage currents from under the insulator.

The invention provides an isolation structure and a manufacturing method thereof for a high-voltage device in a high-voltage BCD process, the isolation structure comprising: a semiconductor substrate having a first type of doping; an epitaxial layer having a second type of doping over the semiconductor substrate, wherein the first type of doping is opposite to the second type of doping; an isolation region having the first type of doping, wherein the isolation region extends through the epitaxial layer into the semiconductor substrate, and wherein the isolation region has a doping concentration on the same order as a doping concentration of the epitaxial layer; a field oxide layer over the isolation region. This invention effectively isolates the epitaxial island where the BCD high-voltage device is located, thereby increasing the breakdown voltage of the high-voltage device in the BCD process. Further, with a minimum thickness of the field oxide layer, the parasitical threshold voltage between the aluminum wiring and the silicon surface of the high-voltage device can be higher than 1200V, thereby improving the planarization of oxide layer steps on the silicon surface in the whole high-voltage BCD process, and enhancing the reliability of the product.

A semiconductor device includes a substrate including a first active pattern and a second active pattern, a device isolation layer filling a first trench between the first and second active patterns, the device isolation layer including a silicon oxide layer doped with helium, a helium concentration of the device isolation layer being higher than a helium concentration of the first and second active patterns, and a gate electrode crossing the first and second active patterns.

A semiconductor device includes a substrate including a first active pattern and a second active pattern, a device isolation layer filling a first trench between the first and second active patterns, the device isolation layer including a silicon oxide layer doped with helium, a helium concentration of the device isolation layer being higher than a helium concentration of the first and second active patterns, and a gate electrode crossing the first and second active patterns.

A semiconductor device includes a substrate including a first active pattern and a second active pattern, a device isolation layer filling a first trench between the first and second active patterns, the device isolation layer including a silicon oxide layer doped with helium, a helium concentration of the device isolation layer being higher than a helium concentration of the first and second active patterns, and a gate electrode crossing the first and second active patterns.

A semiconductor device includes a substrate including a first active pattern and a second active pattern, a device isolation layer filling a first trench between the first and second active patterns, the device isolation layer including a silicon oxide layer doped with helium, a helium concentration of the device isolation layer being higher than a helium concentration of the first and second active patterns, and a gate electrode crossing the first and second active patterns.

The invention provides an isolation structure and a manufacturing method thereof for a high-voltage device in a high-voltage BCD process, the isolation structure comprising: a semiconductor substrate having a first type of doping; an epitaxial layer having a second type of doping over the semiconductor substrate, wherein the first type of doping is opposite to the second type of doping; an isolation region having the first type of doping, wherein the isolation region extends through the epitaxial layer into the semiconductor substrate, and wherein the isolation region has a doping concentration on the same order as a doping concentration of the epitaxial layer; a field oxide layer over the isolation region. This invention effectively isolates the epitaxial island where the BCD high-voltage device is located, thereby increasing the breakdown voltage of the high-voltage device in the BCD process. Further, with a minimum thickness of the field oxide layer, the parasitical threshold voltage between the aluminum wiring and the silicon surface of the high-voltage device can be higher than 1200V, thereby improving the planarization of oxide layer steps on the silicon surface in the whole high-voltage BCD process, and enhancing the reliability of the product.

A semiconductor structure is provided. The semiconductor structure includes a substrate, a first oxide layer disposed over the substrate, a second oxide layer, and a semiconductor layer disposed over the second oxide layer. The second oxide layer is disposed at one side of the first oxide layer and is in contact with the first oxide layer. The second oxide layer partially overlaps the first oxide layer, and the first oxide layer and the second oxide layer include the same oxide.

A semiconductor structure is provided. The semiconductor structure includes a substrate, a first oxide layer disposed over the substrate, a second oxide layer, and a semiconductor layer disposed over the second oxide layer. The second oxide layer is disposed at one side of the first oxide layer and is in contact with the first oxide layer. The second oxide layer partially overlaps the first oxide layer, and the first oxide layer and the second oxide layer include the same oxide.

A semiconductor device includes a substrate including a first active pattern and a second active pattern, a device isolation layer filling a first trench between the first and second active patterns, the device isolation layer including a silicon oxide layer doped with helium, a helium concentration of the device isolation layer being higher than a helium concentration of the first and second active patterns, and a gate electrode crossing the first and second active patterns.