Robust semiconductor power devices with design to protect transistor cells with slower switching speed

Patent metadata

Field	Value
Publication number	US-10032584-B2
Application number	US-201414585201-A
Country	US
Kind code	B2
Filing date	Dec 30, 2014
Priority date	Mar 3, 2008
Publication date	Jul 24, 2018
Grant date	Jul 24, 2018

Abstract

This invention discloses a power switch that includes a fast-switch semiconductor power device and a slow-switch semiconductor power device controllable to turn on and off a current transmitting therethrough. The slow-switch semiconductor power device further includes a ballasting resistor for increasing a device robustness of the slow switch semiconductor power device. In an exemplary embodiment, the fast-switch semiconductor power device includes a fast switch metal oxide semiconductor field effect transistor (MOSFET) and the slow-switch semiconductor power device includes a slow switch MOSFET wherein the slow switch MOSFET further includes a source ballasting resistor.

First claim

We claim:

1. A method for manufacturing a switch comprising:
manufacturing a fast-switch semiconductor power device and a slow-switch semiconductor power device each having a gate to apply a gate voltage thereon for controlling a turn-on and turn-off of a current transmitting therethrough wherein the step of manufacturing said slow-switch semiconductor power device further comprising a step of connecting a robustness increasing circuit to said slow-switch semiconductor power device to handle a higher current and a higher voltage than said fast-switch semiconductor power device and wherein the step further comprising a step of connecting the gate of the slow-switch semiconductor power device through a resistor to the gate of the fast-switch semiconductor power device.

2. The method of claim 1 wherein:
said step of connecting the robustness-increasing circuit to the slow-switch semiconductor power device further includes a step of connecting a ballasting resistor as the robustness-increasing circuit to the gate of said slow-switch semiconductor power device.

3. The method of claim 1 wherein:
said step of manufacturing said fast-switch semiconductor power device and said slow switch semiconductor power device further comprising a step of manufacturing a fast switch metal oxide semiconductor field effect transistor (MOSFET) and a slow switch MOSFET by connecting a ballasting resistor as the robustness-increasing circuit to the gate of the slow switch MOSFET.

4. The method of claim 1 wherein:
said step of manufacturing said slow-switch semiconductor power device further including a step of manufacturing said slow-switch semiconductor power device in a plurality of regions distributed over a semiconductor chip by connecting a ballasting resistor as the robustness-increasing circuit to the gate of the slow switch semiconductor power device in a plurality of regions distributed over the semiconductor chip.

5. The method of claim 1 wherein:
said step of manufacturing said slow-switch semiconductor power device further including a step of disposing said slow-switch semiconductor power device near approximately a central location of a semiconductor chip by connecting a ballasting resistor as the robustness-increasing circuit to the gate of the slow switch semiconductor power device near approximately a central location of the semiconductor chip.

6. The method of claim 1 wherein:
said step of manufacturing said slow-switch semiconductor power device further including a step of disposing said slow-switch semiconductor power device near approximately a peripheral location of a semiconductor chip by connecting a ballasting resistor as the robustness-increasing circuit to the gate of the slow switch semiconductor power device near approximately a peripheral location of the semiconductor chip.

7. The method of claim 1 wherein:
said step of manufacturing said fast-switch and slow-switch semiconductor power devices comprising a step of manufacturing a plurality of fast switch MOSFET cells and a plurality of slow switch MOSFET cells by forming each of said slow switch MOSFET cells with a source ballasting resistor and by connecting a ballasting resistor as the robustness-increasing circuit to the source of the slow switch MOSFET cells.

8. The method of claim 1 wherein:
said step of manufacturing said fast-switch and slow-switch semiconductor power devices comprising a step of manufacturing a plurality of fast switch MOSFET cells and a plurality of slow switch MOSFET cells and manufacturing each of said slow switch MOSFET cells with a source having an greater length with a higher resistance than said fast switch MOSFET cells.

9. The method of claim 1 wherein:
said step of manufacturing said fast-switch and slow-switch semiconductor power devices comprising a step of manufacturing a plurality of fast switch MOSFET cells and a plurality of slow switch MOSFET cells and manufacturing each of said slow switch MOSFET cells with a source having a lower source dopant concentration with a higher resistance than said fast switch MOSFET cells.

Assignees

• Lui Sik K
• Bhalla Anup
• Alpha & Omega Semiconductor

Inventors

• Lui Sik K
• Bhalla Anup

Classifications

• H03K17/687

  the devices being field-effect transistors · CPC title

• H03K17/04123

  in field-effect transistor switches · CPC title

• Y10T29/49105

  Switch making · CPC title

• H03K17/164

  using parallel switching arrangements · CPC title

• H03K17/08122

  in field-effect transistor switches · CPC title