Abstract: The application discloses a hand-held fan, including a main housing. The main housing includes a cylindrical holding part and a semi-cylindrical mounting part. The hand-held fan also includes a set of protection covers provided at the mounting part. The protection cover is also provided with a connecting part rotatably connected to the mounting part. An outer side of the mounting part is opened and provided with an annular slot, the connecting part is provided with a plurality of catch platforms clamped and connected to the annular slots, two limit grooves are symmetrically provided in the annular slot along a rotating axial direction of the fan blade, and the inner side of the connecting part is provided with two limit bosses clamped and connected to the two limit grooves. This application solves the problem that an existing small hand-held fan cannot effectively protect the fan blade.

Abstract: A parasitic lateral PNP transistor is disclosed, in which, an N-type implanted region formed in each of two adjacent active regions forms a base region; a P-type doped polysilicon pseudo buried layer located under a shallow trench field oxide region between the two active regions serves as an emitter; and a P-type doped polysilicon pseudo buried layer located under each of the shallow trench field oxide regions on the outer side of the active regions serves as a collector region. The transistor has a C-B-E-B-C structure which alters the current path in the base region to a straight line, which can improve the current amplification capacity of the transistor and thus leads to a significant improvement of its current gain and frequency characteristics, and is further capable of reducing the area and increasing current intensity of the transistor. A manufacturing method of the parasitic lateral PNP transistor is also disclosed.

Abstract: A method of filling shallow trenches is disclosed. The method includes: successively forming a first oxide layer and a second oxide layer over the surface of a silicon substrate where shallow trenches are formed in; etching the second oxide layer to form inner sidewalls with an etchant which has a high etching selectivity ratio of the second oxide layer to the first oxide layer; growing a high-quality pad oxide layer by thermal oxidation after the inner sidewalls are removed; and filling the trenches with an isolation dielectric material. By using this method, the risk of occurrence of junction spiking and electrical leakage during a subsequent process of forming a metal silicide can be reduced.

Abstract: A PN-junction varactor in a BiCMOS process is disclosed which comprises an N-type region, a P-type region and N-type pseudo buried layers. Both of the N-type and P-type regions are formed in an active area and contact with each other, forming a PN-junction; the P-type region is situated on top of the N-type region. The N-type pseudo buried layers are formed at bottom of shallow trench field oxide regions on both sides of the active area and contact with the N-type region; deep hole contacts are formed on top of the N-type pseudo buried layers in the shallow trench field oxide regions to pick up the N-type region. A manufacturing method of PN-junction varactor in a BiCMOS process is also disclosed.

Abstract: A SiGe HBT formed on a silicon substrate is disclosed. An active area is isolated by field oxide regions; a collector region is formed in the active area and extends into the bottom of the field oxide regions; pseudo buried layers are formed at the bottom of the field oxide regions, wherein each pseudo buried layer is separated by a lateral distance from the active area and connected to a lateral extension part of the collector region; first deep hole contacts are formed on top of the pseudo buried layers in the field oxide regions to pick up collector electrodes; a plurality of second deep hole contacts with a floating structure, are formed in the field oxide region on top of a lateral extension part of the collector region, wherein N-type implantation regions are formed at the bottom of the second deep hole contacts.

Abstract: The present invention provides a multi-finger structure of a SiGe heterojunction bipolar transistor (HBT). It is consisted of plural SiGe HBT single cells. The multi-finger structure is in a form of C/BEBC/BEBC/.../C, wherein, C, B, E respectively stands for collector, base and emitter; CBEBC stands for a SiGe HBT single cell. The collector region is consisted of an n type ion implanted layer inside the active region. The bottom of the implanted layer is connected to two n type pseudo buried layers. The two pseudo buried layers are formed through implantation to the bottom of the shallow trenches that surround the collector active region. Two collectors are picked up by deep trench contact through the field oxide above the two pseudo buried layers. The present invention can reduce junction capacitance, decrease collector electrode output resistance, and improve device frequency characteristics.

Abstract: A vertical parasitic PNP device in a SiGe HBT process is disclosed which comprises a collector region, a base region, an emitter region, P-type pseudo buried layers and N-type polysilicons. The pseudo buried layers are formed at bottom of shallow trench field oxide regions around the collector region and contact with the collector region; deep hole contacts are formed on top of the pseudo buried layers to pick up collector electrodes. The N-type polysilicons are formed on top of the base region and are used to pick up base electrodes. The emitter region comprises a P-type SiGe epitaxial layer and a P-type polysilicon both of which are formed on top of the base region. A manufacturing method of a vertical parasitic PNP device in a SiGe HBT process is also disclosed.

Abstract: A PN-junction varactor in a BiCMOS process is disclosed which comprises an N-type region, a P-type region and N-type pseudo buried layers. Both of the N-type and P-type regions are formed in an active area and contact with each other, forming a PN-junction; the P-type region is situated on top of the N-type region. The N-type pseudo buried layers are formed at bottom of shallow trench field oxide regions on both sides of the active area and contact with the N-type region; deep hole contacts are formed on top of the N-type pseudo buried layers in the shallow trench field oxide regions to pick up the N-type region. A manufacturing method of PN-junction varactor in a BiCMOS process is also disclosed.

Abstract: A SiGe HBT formed on a silicon substrate is disclosed. An active area is isolated by field oxide regions; a collector region is formed in the active area and extends into the bottom of the field oxide regions; pseudo buried layers are formed at the bottom of the field oxide regions, wherein each pseudo buried layer is separated by a lateral distance from the active area and connected to a lateral extension part of the collector region; first deep hole contacts are formed on top of the pseudo buried layers in the field oxide regions to pick up collector electrodes; a plurality of second deep hole contacts with a floating structure, are formed in the field oxide region on top of a lateral extension part of the collector region, wherein N-type implantation regions are formed at the bottom of the second deep hole contacts.

Abstract: The present invention provides a multi-finger structure of a SiGe heterojunction bipolar transistor (HBT). It is consisted of plural SiGe HBT single cells. The multi-finger structure is in a form of C/BEBC/BEBC/.../C, wherein, C, B, E respectively stands for collector, base and emitter; CBEBC stands for a SiGe HBT single cell. The collector region is consisted of an n type ion implanted layer inside the active region. The bottom of the implanted layer is connected to two n type pseudo buried layers. The two pseudo buried layers are formed through implantation to the bottom of the shallow trenches that surround the collector active region. Two collectors are picked up by deep trench contact through the field oxide above the two pseudo buried layers. The present invention can reduce junction capacitance, decrease collector electrode output resistance, and improve device frequency characteristics.