Temperature sensor calibration wafer structure and method of fabrication

• US 5,436,494 A
• Filed: 01/12/1994
• Issued: 07/25/1995
• Est. Priority Date: 01/12/1994
• Status: Expired due to Term

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Moslehi, Mehrdad M.
• Primary Examiner(s): Jackson, Jerome
• Assistant Examiner(s): Monin, Jr., Donald L.
• Application Number:
  US08/180,251
• Time in Patent Office: 559 Days
• Field of Search: 257/467, 257/468, 257/537, 338/308, 338/319
• US Class Current: 257/467
• CPC Class Codes: G01K 7/00 Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat giving results other than momentary value of temperature G01K3/00 ; Power supply therefor, e.g. using thermoelectric elements

Abstract

An embodiment of the present invention relates to a semiconductor wafer structure, the wafer structure comprising: a semiconductor substrate; a plurality of temperature sensing elements (12) disposed over the semiconductor substrate, where temperature sensing elements (12) are fabricated so that an electrical characteristic of the temperature sensing element changes as the temperature of the wafer changes; and a plurality of interconnection lines (10, 14) connecting the temperature sensing elements (12) to external devices. In addition the semiconductor wafer structure includes a passivation layer which is deposited over the semiconductor substrate and the temperature sensing elements. The temperature sensing elements are comprised of a refractory conductor, the refractory conductor has a temperature dependent electrical resistivity and has a width much less than its length. The interconnection lines are comprised of a conductor, and the conductor has a width which is greater than the width of the refractory conductor of the temperature sensor conductor. One or more electrical characteristic of the temperature sensing elements changes with temperature. These electrical characteristic could be either: conductor resistance, dielectric capacitance, diode characteristics, or inductance.

Claims

1. A temperature sensor integrated into a semiconductor wafer such that said temperature sensor is integrated into said semiconductor wafer so that an electrical characteristic of said temperature sensor changes as the temperature of said semiconductor wafer changes, and said temperature sensor comprising:

a first conductor, formed from a first conductive material and having a width;

a second conductor, formed from said first conductive material and having a width approximately equal to the width of said first conductor; and

a third conductor, formed from a second conductive material, disposed between said first and second conductors, and having a length and a width, said width of said third conductor being less then said width of said first or second conductors and much less then said length of said third conductor;

wherein the resistance of said third conductor is greater then the resistance of said first or second conductors, and a change in resistance of said first and second conductors due to temperature changes will be much less then the change in resistance of said third conductor due to said temperature change.