Platinum film resistor device

• US 4,129,848 A
• Filed: 07/05/1977
• Issued: 12/12/1978
• Est. Priority Date: 09/03/1975
• Status: Expired due to Term

• Current Assignee: Raytheon Company (Rtx Corporation)
• Original Assignee: Raytheon Company (Rtx Corporation)
• Inventors: Salzer, Thomas E., Frank, Robert I.
• Primary Examiner(s): Mack, John H.
• Assistant Examiner(s): Leader, William
• Application Number:
  US05/812,866
• Time in Patent Office: 525 Days
• Field of Search: 204/192 F, 204/192 E, 204/192 EC, 204/192 D, 338/25, 338/26, 338/28, 338/306, 338/308, 338/309, 338/211, 338/252, 73/295, 73/362 AR
• US Class Current: 338/308
• CPC Class Codes: G01F 23/247 for discrete levels
• CPC Class Codes: H01C 17/12 by sputtering
• CPC Class Codes: H01C 7/021 formed as one or more layers or coatings
• CPC Class Codes: H01C 7/22 Elongated resistive element being bent or curved, e.g. sinusoidal, helical

Abstract

A platinum film resistor device and method for making the same. A layer of quartz, deposited upon an insulative substrate preferably silicon, is sputter etched at high power levels to produce etch pits in the surface thereof. A layer of platinum is then deposited over the quartz layer by first sputtering platinum at high power for a relatively short period of time and then completing the layer by continuing to sputter deposit platinum at a lower power. A second layer of quartz is deposited over the layer of platinum and the second layer of quartz masked and chemically etched away in the regions where portions of the platinum layer are to be removed. The exposed platinum and a portion of the second quartz layer are then sputter etched away leaving the platinum in a predetermined configuration. The platinum is then annealed, the second quartz layer removed above the lead bonding pads, and external leads attached. The device is particularly useful in temperature measuring application.

Claims

1. The product comprising a platinum film resistor produced by the process comprising the steps of:

providing a silicon substrate;

growing a layer of silicon dioxide upon at least one surface of said substrate;

sputter etching said layer of silicon dioxide to produce a plurality of etch pits upon one surface thereof;

sputtering depositing a first quantity of platinum upon said surface of said layer of silicon dioxide at a first sputter power level and first time period;

sputter depositing a second quantity of platinum upon said first quantity of platinum at a second sputter power level and second time period;

sputter depositing a layer of quartz over said platinum;

producing openings in said layer of quartz in a predetermined configuration;

sputter etching portions of said platinum through said openings in said layer of quartz; and

attaching one or more leads to the remaining portions of said platinum.

2. The product of claim 1 wherein said first power level is greater than said second power level and said first time period is less than said second time period.

3. The product of claim 2 further comprising the step of:

annealing said platinum.

4. The product of claim 3 further comprising the step of:

depositing a second layer of quartz.

5. The product of claim 3 wherein said step of sputter etching said layer of silicon dioxide comprises:

sputter etching said layer of silicon dioxide with a minimum sputtering power level of 2 watts per square inch.

6. The product of claim 5 wherein said first power level is in the range of 50 to 100 watts per square inch and said first time period is in the range of 2 to 20 seconds.