Protection device and related fabrication methods

• US 9,543,420 B2
• Filed: 07/19/2013
• Issued: 01/10/2017
• Est. Priority Date: 07/19/2013
• Status: Active Grant

• Current Assignee: NXP USA, Inc. (NXP Semiconductors NV)
• Original Assignee: NXP USA, Inc. (NXP Semiconductors NV)
• Inventors: Chen, Wen-Yi, Gill, Chai Ean
• Primary Examiner(s): SHINGLETON, MICHAEL B
• Application Number:
  US13/946,613
• Publication Number:
  US 20150021739A1
• Time in Patent Office: 1,271 Days
• Field of Search: 257/477, 257/557, 257/E27.023
• US Class Current: 1/1
• CPC Class Codes: H01L 27/0259 using bipolar transistors as protective elements
• CPC Class Codes: H01L 29/0821 Collector regions of bipolar transistors
• CPC Class Codes: H01L 29/1008 of lateral transistors
• CPC Class Codes: H01L 29/6625 Lateral transistors H01L29/66242 and H01L29/66265 take precedence
• CPC Class Codes: H01L 29/73 Bipolar junction transistors
• CPC Class Codes: H01L 29/735 Lateral transistors

Abstract

Protection device structures and related fabrication methods are provided. An exemplary semiconductor protection device includes a base region of semiconductor material having a first conductivity type, an emitter region within the base region having the opposite conductivity type, and a collector region of semiconductor material having the second conductivity type, wherein at least a portion of the base region resides between the emitter region and the collector region. A depth of the collector region is greater than a depth of the emitter region and less than or equal to a depth of the base region such that a distance between a lateral boundary of the emitter region and a proximal lateral boundary of the collector region is greater than zero and the collector region does not overlap or otherwise underlie the emitter region.

Claims

1. A semiconductor device comprising:

a first region of semiconductor material having a first conductivity type and a first dopant concentration;

a base well region within the first region, the base well region having the first conductivity type and a second dopant concentration greater than the first dopant concentration of the first region;

a base contact region within the base well region, the base contact region having the first conductivity type and a third dopant concentration greater than the first dopant concentration;

an emitter region of semiconductor material within the base well region, the emitter region having a second conductivity type opposite the first conductivity type; and

a collector region of semiconductor material having the second conductivity type, wherein;

at least a portion of the first region resides between the emitter region and the collector region;

a depth of the collector region is greater than a depth of the emitter region;

a depth of a second portion of the first region underlying the emitter region is greater than or equal to the depth of the collector region;

at least a portion of the base well region resides between the emitter region and the collector region; and

the depth of the collector region is greater than a depth of the base well region.

4. The semiconductor device of claim 1, wherein:

the first region and the emitter region are coupled to a first terminal; and

the collector region is coupled to a second terminal.

5. The semiconductor device of claim 1, wherein a distance between a lateral boundary of the emitter region and a proximal lateral boundary of the collector region is greater than zero.

6. The semiconductor device of claim 1, wherein the collector region does not extend laterally underneath the emitter region.

7. The semiconductor device of claim 1, wherein the collector region contacts an underlying layer of dielectric material.

8. The semiconductor device of claim 7, wherein the second portion abuts the underlying layer of dielectric material.

9. The semiconductor device of claim 1, further comprising:

an isolation region within the first region, wherein;

the isolation region resides laterally between the base contact region and the emitter region; and

the base contact region and the emitter region are electrically connected.

10. The semiconductor device of claim 1, further comprising:

a first interface;

a second interface; and

functional circuitry coupled between the first interface and the second interface, wherein;

the base contact region and the emitter region are coupled to the first interface; and

the collector region is coupled to the second interface.

11. The semiconductor device of claim 1, further comprising an isolation region within the base well region, wherein:

the isolation region resides laterally between the base contact region and the emitter region; and

the base contact region and the emitter region are electrically connected.

14. The semiconductor device of claim 1, further comprising:

a second region of semiconductor material having the first conductivity type; and

a second emitter region of semiconductor material having the second conductivity type, wherein;

a third portion of the second region resides between the second emitter region and the collector region;

the depth of the collector region is greater than a depth of the second emitter region; and

a depth of the second region is greater than or equal to the depth of the collector region.

15. The semiconductor device of claim 14, wherein:

the first region, the emitter region, the second region, and the second emitter region are coupled to a first terminal; and

the collector region is coupled to a second terminal.

16. The semiconductor device of claim 14, further comprising:

a third emitter region of semiconductor material having the second conductivity type; and

a second collector region of semiconductor material having the second conductivity type, wherein;

a fourth portion of the second region resides between the third emitter region and the second collector region;

a depth of the second collector region is greater than a depth of the third emitter region; and

the depth of the second region is greater than or equal to a depth of the second collector region.

2. A semiconductor device comprising:

a first region of semiconductor material having a first conductivity type and a first dopant concentration;

a base well region within the first region, the base well region having the first conductivity type and a second dopant concentration greater than the first dopant concentration of the first region;

a base contact region within the base well region, the base contact region having the first conductivity type and a third dopant concentration greater than the first dopant concentration;

an emitter region of semiconductor material within the base well region, the emitter region having a second conductivity type opposite the first conductivity type; and

a collector region of semiconductor material having the second conductivity type, wherein;

at least a portion of the first region resides between the emitter region and the collector region;

a depth of the collector region is greater than a depth of the emitter region;

a depth of a second portion of the first region underlying the emitter region is greater than or equal to the depth of the collector region; and

the collector region comprises;

a well region of semiconductor material having the second conductivity type and a first dopant concentration; and

a buried region of semiconductor material underlying the well region, the buried region having the second conductivity type and a second dopant concentration greater than or equal to the first dopant concentration.

12. The semiconductor device of claim 2, wherein the buried region does not extend laterally underneath the emitter region.

13. The semiconductor device of claim 2, wherein lateral boundaries of the well region are substantially aligned with lateral boundaries of the buried region.

17. The semiconductor device of claim 2, wherein the base contact region and the emitter region are electrically connected.

18. The semiconductor device of claim 17, further comprising:

a first interface;

a second interface; and

functional circuitry coupled between the first interface and the second interface, wherein;

the base contact region and the emitter region are coupled to the first interface; and

the collector region is coupled to the second interface.

19. The semiconductor device of claim 2, wherein:

the first region and the emitter region are coupled to a first terminal; and

the collector region is coupled to a second terminal.

20. The semiconductor device of claim 2, wherein a distance between a lateral boundary of the emitter region and a proximal lateral boundary of the collector region is greater than zero.

3. A semiconductor device comprising:

a first region of semiconductor material having a first conductivity type;

an emitter region of semiconductor material having a second conductivity type opposite the first conductivity type;

a collector region of semiconductor material having the second conductivity type; and

a base well region within the first region, the base well region having the emitter region formed therein, the base well region having the first conductivity type and a first dopant concentration greater than a second dopant concentration of the first region by a factor of at least 10, wherein;

at least a portion of the first region resides between the emitter region and the collector region;

a depth of the collector region is greater than a depth of the emitter region;

a depth of a second portion of the first region underlying the emitter region is greater than or equal to the depth of the collector region;

a distance between a lateral boundary of the base well region and a proximal lateral boundary of the collector region is greater than zero; and

the portion of the first region resides between the collector region and the base well region.