Song Shuxiang

Thin silicon layer SOI power device with linearly-distance fixed charge islands

A new high-voltage LDMOS with linearly-distanced fixed charge islands is proposed (LFI LDMOS). A lot of linearly-distanced fixed charge islands are introduced by implanting the Cs or I ion into the buried oxide layer and dynamic holes are attracted and accumulated, which is crucial to enhance the electric field of the buried oxide and the vertical breakdown voltage. The surface electric field is improved by increasing the distance between two adjacent fixed charge islands from source to drain, which lead to the higher concentration of the drift region and a lower on-resistance. The numerical results indicate that the breakdown voltage of 500 V with L d = 45 μm is obtained in the proposed device in comparison to 209 V of conventional LDMOS, while maintaining low on-resistance.

Automatic sorting system design for long bamboo batten

To effectively and precisely drive industrial cameras to photograph and then sort long bamboo battens, a surface-defect and color detection device and a sorting device are designed. Further, a sectionalized photography program and sorting program design is proposed. The overall machine employs STM32 as the core master controller, which is connected to the relay drive plate, the photoelectric switch, the industrial camera, etc., for control, to photograph bamboo battens of different lengths in sections, and to sort six types of bamboo batten according to the bamboo-batten category signal sent by the upper computer. Devices for improving bamboo-product processing system efficiency and enhancing the level of automation of modern agricultural products, such as the proposed design, are of considerable importance.

New SOI power device with multi-region high-concentration fixed interface charge and the model of breakdown voltage*

A new SOI power device with multi-region high-concentration fixed charge (MHFC) is reported. The MHFC is formed through implanting Cs or I ion into the buried oxide layer (BOX), by which the high-concentration dynamic electrons and holes are induced at the top and bottom interfaces of BOX. The inversion holes can enhance the vertical electric field and raise the breakdown voltage since the drain bias is mainly generated from the BOX. A model of breakdown voltage is developed, from which the optimal spacing has also been obtained. The numerical results indicate that the breakdown voltage of device proposed is increased by 287% in comparison to that of conventional LDMOS.