Semiconductor device having resistance elements and fabrication method thereof

• US 10,014,363 B2
• Filed: 01/10/2017
• Issued: 07/03/2018
• Est. Priority Date: 02/19/2016
• Status: Active Grant

• Current Assignee: Mie Fujitsu Semiconductor Ltd (United Microelectronics Corporation)
• Original Assignee: Mie Fujitsu Semiconductor Ltd (United Microelectronics Corporation)
• Inventors: Ema, Taiji, Misawa, Nobuhiro, Kumeno, Kazuyuki, Yasuda, Makoto
• Primary Examiner(s): Bachner, Robert
• Assistant Examiner(s): REIDA, MOLLY KAY
• Application Number:
  US15/402,367
• Publication Number:
  US 20170243934A1
• Time in Patent Office: 539 Days
• CPC Class Codes: H01L 27/0629 in combination with diodes, or resistors, or capacitors
• CPC Class Codes: H01L 27/0802 Resistors only
• CPC Class Codes: H01L 28/20 Resistors

Abstract

A semiconductor device includes as a resistance element a first polycrystalline silicon and a second polycrystalline silicon containing impurities, such as boron, of the same kind and having different widths. The first polycrystalline silicon contains the impurities at a concentration C_X. The second polycrystalline silicon has a width larger than a width of the first polycrystalline silicon and contains the impurities of the same kind at a concentration C_Y lower than the concentration C_X. A sign of a temperature coefficient of resistance (TCR) of the first polycrystalline silicon changes at the concentration C_X. A sign of a TCR of the second polycrystalline silicon changes at the concentration C_Y.

Claims

1. A semiconductor device comprising:

a first polycrystalline silicon containing first impurities at a first concentration and having a first width; and

a second polycrystalline silicon containing the first impurities at a second concentration lower than the first concentration and having a second width larger than the first width,

wherein;

a sign of a temperature coefficient of the first polycrystalline silicon changes at the first concentration;

a sign of a temperature coefficient of the second polycrystalline silicon changes at the second concentration; and

the first polycrystalline silicon and the second polycrystalline silicon are formed as continuous one body and electrically connected.

2. The semiconductor device according to claim 1, wherein the first concentration and the second concentration are higher than or equal to 1×

10²⁰ cm<sup>−

3</sup> and lower than or equal to 1×

10²¹ cm<sup>−

3</sup>.

3. The semiconductor device according to claim 1, wherein the first impurities are p-type impurities.

4. The semiconductor device according to claim 1, wherein the first polycrystalline silicon and the second polycrystalline silicon are electrically connected in series.

5. A semiconductor device comprising:

a first polycrystalline silicon containing first impurities at a first concentration and having a first width; and

a second polycrystalline silicon containing the first impurities at a second concentration lower than the first concentration and having a second width larger than the first width,

wherein;

a sign of a temperature coefficient of the first polycrystalline silicon changes at the first concentration;

a sign of a temperature coefficient of the second polycrystalline silicon changes at the second concentration; and

a first sheet resistance of the first polycrystalline silicon and a second sheet resistance of the second polycrystalline silicon are equal or almost equal.

6. The semiconductor device according to claim 5, wherein the first concentration and the second concentration are higher than or equal to 1×

10²⁰ cm<sup>−

3</sup> and lower than or equal to 1×

10²¹ cm<sup>−

3</sup>.

7. The semiconductor device according to claim 5, wherein the first polycrystalline silicon and the second polycrystalline silicon are formed as continuous one body and electrically connected.

8. The semiconductor device according to claim 5, wherein the first impurities are p-type impurities.

9. The semiconductor device according to claim 7, wherein the first polycrystalline silicon and the second polycrystalline silicon are electrically connected in series.