Laterally high-voltage MOSFET and manufacturing method thereof

A technology of lateral high voltage and manufacturing method, which is applied in semiconductor/solid-state device manufacturing, electrical components, circuits, etc., can solve the problems of rising on-resistance, etc., and achieve the goals of reducing electric field peak value, small on-resistance, and improving breakdown voltage Effect

Active Publication Date: 2013-11-27
UNIV OF ELECTRONICS SCI & TECH OF CHINA +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In the design of power LDMOS (Latral Double-diffused MOSFET) devices, breakdown voltage (Breakdown Voltage, BV) and specific on-resistance (Specific on-resistance, R on,sp ) has a contradictory relationship: R on,sp ∝BV 2.3～2.6 , so when the device is applied at high voltage, the on-resistance rises sharply, which limits the application of high-voltage LDMOS devices in high-voltage power integrated circuits, especially in circuits that require low conduction loss and small chip area
In order to overcome the problem of high on-resistance, J.A.APPLES et al. proposed RESURF (Reduced SURface Field) to reduce the surface field technology, which is widely used in the design of high-voltage devices. Although the on-resistance is effectively reduced, the breakdown voltage The contradictory relationship between the on-resistance and the on-resistance still needs to be further improved

Method used

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  • Laterally high-voltage MOSFET and manufacturing method thereof
  • Laterally high-voltage MOSFET and manufacturing method thereof
  • Laterally high-voltage MOSFET and manufacturing method thereof

Examples

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Embodiment 1

[0061] The adopted process of this example is that the second conductivity type semiconductor heavily doped layer 5 has a plurality of smaller ion implantation windows, the size of the small windows is the same, and the spacing of the windows is different, along with the second conductivity type semiconductor drain region 10 approaching, the injection window gradually decreases, as Figure 4 shown. Figure 5 It is a cross-sectional view of the device structure after implantation of semiconductor impurities of the second conductivity type. In the figure, the semiconductor impurities 15 of the second conductivity type are diffused by annealing to form a heavily doped layer 5 of the semiconductor of the second conductivity type with a linear doping distribution, such as Figure 6 shown. At the same time, the field oxide layer 6 is formed before the ion implantation process of the first conductivity type semiconductor field drop layer 4 , the field oxide layer 6 is formed first, ...

Embodiment 2

[0063] The process used in this example is to first form the first conductive type semiconductor field drop layer 4 and the second conductive type semiconductor heavily doped layer 5, and then form the field oxide layer 6, the first conductive type semiconductor field drop layer 4, The second conductivity type semiconductor heavily doped layer 5 and the field oxide layer 6 are annealed together. At the same time, the second conductivity type semiconductor heavily doped layer 5 has a plurality of smaller ion implantation windows, the size of the implantation windows is the same, the spacing is different, and the window spacing gradually decreases as it approaches the second conductivity type semiconductor drain region 10, Such as Figure 7 shown. Figure 8 It is a cross-sectional view of the device structure after implantation of semiconductor impurities of the second conductivity type. In the figure, the semiconductor impurities 15 of the second conductivity type are diffused...

Embodiment 3

[0065] The adopted process of this example is that the second conductivity type semiconductor heavily doped layer 5 has a plurality of smaller ion implantation windows, the spacing of the small windows is the same, and the size of the windows is different, as the second conductivity type semiconductor drain region 10 approaches gradually decrease, as Figure 10 shown. Figure 11 It is a cross-sectional view of the device structure after implantation of semiconductor impurities of the second conductivity type. In the figure, the semiconductor impurities 15 of the second conductivity type are diffused by annealing to form a heavily doped layer 5 of the semiconductor of the second conductivity type with a linear doping distribution, such as Figure 12 shown. At the same time, the field oxide layer 6 is formed before the ion implantation process of the first conductivity type semiconductor field drop layer 4 , the field oxide layer 6 is formed first, and the annealing process of ...

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Abstract

The invention relates to semiconductor technologies, in particular to a laterally high-voltage MOSFET and a manufacturing method thereof. The laterally high-voltage MOSFET is characterized in that a first-kind conduction type semiconductor field dropping layer is formed in a second conduction type semiconductor drift region through photoetching and ion implantation technologies, and a second conduction type semiconductor heavy doping layer is formed on the surface of the second conduction type semiconductor drift region through the photoetching and ion implantation technologies. The laterally high-voltage MOSFET has the advantages that under the circumstance that high breakdown voltage is guaranteed, specific on-resistance of the MOSFET can be greatly reduced, meanwhile the electric field peak value of the source end of the laterally high-voltage MOSFET is reduced, high-field effects are avoided, breakdown voltage of the MOSFET is improved, the MOSFET has lower on-resistance and a smaller chip area under the condition of the same breakover capacity, and a surface electric field of the MOSFET is well optimized; meanwhile, the manufacturing method is simple, low in technological difficulty and especially suitable for the laterally high-voltage MOSFET.

Description

technical field [0001] The invention relates to semiconductor technology, in particular to a lateral high-voltage MOSFET and a manufacturing method thereof. Background technique [0002] Lateral high-voltage MOSFET is an essential part of the development of high-voltage power integrated circuits. High-voltage power devices require high breakdown voltage, low on-resistance and low switching loss. To achieve a high breakdown voltage in a lateral high voltage MOSFET, the drift region used to withstand the voltage is required to have a long size and low doping concentration. However, in order to meet the low on-resistance of the device, the drift region used as a current channel is required to have a high doping concentration. In the design of power LDMOS (Latral Double-diffused MOSFET) devices, breakdown voltage (Breakdown Voltage, BV) and specific on-resistance (Specific on-resistance, R on,sp ) has a contradictory relationship: R on,sp ∝BV 2.3～2.6 , Therefore, when the de...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01L29/78H01L29/06H01L21/336
Inventor 乔明李燕妃周锌吴文杰许琬陈涛胡利志张波
Owner UNIV OF ELECTRONICS SCI & TECH OF CHINA
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