Bipolar CMOS DMOS (BCD) integrated device based on N type extension layer and manufacture method thereof

Abstract

A bipolar CMOS DMOS (BCD) integrated device based on a N type extension layer and a manufacture method thereof, which belongs to the semiconductor power device technology field, are disclosed. In the invention, a high voltage nLDMOS device, a high voltage nLIGB device, a low voltage PMOS device, a low voltage NMOS device, a low voltage PNP device and a low voltage NPN device are integrated on a same substrate. All devices are made in an N type extension layer arranged on a surface of a P type extension layer which is on a surface of a P type substrate. And junction isolations of the devices are realized through P<+> isolation regions. N type buried layers are arranged between the P type substrate and the P type extension layer, wherein the P type substrate and the P type extension layer are under the high voltage devices. N type buried layers are/ are not arranged between the P type extension layer and the N type extension layer, wherein the P type extension layer and the N type extension layer are under the low voltage devices. The N type buried layers are introduced in the invention to realize that silicon chips with lower resistivity can be used as the substrate at a same breakdown voltage. In the prior art, float-zone technique is adopted to manufacture monocrystalline silicon pieces, which can increase the chip manufacturing costs. In the invention, the float-zone technique is not used so that the chip manufacturing costs can be reduced.

Description

Technical field [0001] The invention belongs to the technical field of semiconductor power devices. Background technique [0002] BCD (Bipolar CMOS DMOS) process technology utilizes the high analog accuracy of Bipolar transistors, the high integration of CMOS and the high power characteristics of DMOS (Double-diffused MOSFET) to realize Bipolar analog circuits, CMOS logic circuits, CMOS analog circuits and DMOS high voltage Monolithic integration of power devices. Lateral high voltage power devices LDMOS (Lateral Double-diffused MOSFET) and LIGBT (Lateral Insulated Gate Bipolar Trasistor) are easily compatible with traditional CMOS devices, so they have been widely used in the field of smart power integrated circuits. The primary purpose of the design of a horizontal high voltage power device is to achieve a rated breakdown voltage under a given drift zone length, and its breakdown voltage is determined by the lowest value of the lateral surface withstand voltage and the longitu...

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Problems solved by technology

In order to improve the vertical body withstand voltage of the device, high-resistivity silicon wafers are usually used as substrates, but high-resistance wafers (>100Ω·cm) are usually manufactured by zone melting, which increases the cost of silicon wafers

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