Test method for measuring metal of silicon wafer body

Abstract

The invention provides a test method for measuring metal of a silicon wafer body, and belongs to the field of semiconductor manufacturing. The test method comprises the steps of 1, taking a silicon wafer with a diameter being 4-10 inch and infinite resistivity; 2, uploading the silicon wafer onto an infrared heating furnace for temperature rising to 200-300 DEG C, and performing constant-temperature baking for 1.5-2.5 hours; 3, uploading the silicon wafer to a full-automatic surface metal collection system; 4, blowing hydrofluoric acid steam to a surface of the silicon wafer for 4-6 minutes bythe full-automatic surface metal collection system during the sample making process; 5, sucking an extraction liquid by a nozzle of the full-automatic surface metal collection system, and recycling metal ions from the surface of the silicon wafer; and 6, testing metal content of a scanning liquid by an inductance coupling plasma mass spectrometer, wherein the tested surface metal content is metalion overflow quantity baked by the infrared heating furnace. The test method is wider in test range, higher in accuracy and lower in cost, and the diameter and the resistivity of the tested silicon wafer are not limited.

Description

technical field [0001] The invention belongs to the field of semiconductor manufacturing, and relates to a test method for measuring silicon wafer bulk metal. Background technique [0002] It is difficult to test the bulk metal of silicon wafers in the semiconductor manufacturing industry, the cost of bulk metal testing is too high, the scanning fluid cannot be recovered when testing heavily doped silicon wafers, large-diameter silicon wafers cannot be tested, and due to the waste of time, the daily monitoring of bulk metals cannot be achieved. question. The traditional test method is to use ozone + hydrofluoric acid vapor to corrode, recover metal ions on the surface of the corroded silicon wafer, use a high-precision balance to record the weight of the corroded silicon wafer, and calculate the corrosion volume through the weight difference, inductively coupled plasma mass spectrometry The instrument tests the metal content of the scanning liquid, so that according to the ...

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Problems solved by technology

[0002] It is difficult to test the bulk metal of silicon wafers in the semiconductor manufacturing industry, the cost of bulk metal testing is too high, the scanning fluid cannot be recovered when testing heavily doped silicon wafers, large-diameter silicon wafers cannot be tested, and due to the waste of time, the daily monitoring of bulk metals cannot be achieved. question

The traditional test method is to use ozone + hydrofluoric acid vapor to corrode, recover metal ions on the surface of the corroded silicon wafer, use a high-precision balance to record the weight of the corroded silicon wafer, and calculate the corrosion volume through the weight difference, inductively coupled plasma mass spectrometry The instrument tests the metal content of the scanning liquid, so that according to the ozone + hydrofluoric acid vapor (HF+O 3 ) The corroded volume and the surface metal ion content calculate the metal ion content per unit volume of the silicon wafer. The traditional test method has the following disadvantages. 1. Due to the influence of the volume of the balance, it cannot test large-diameter silicon wafers; 2. After being corroded, it is rough Influenced by degree of influence, when the resistivity of the silicon wafer is less than 1Ω.cm, the inductively coupled plasma mass spectrometer cannot recover the scanning fluid and cannot test; 3. The cost of testing a 6-inch silicon wafer is 251.53 yuan / piece, which is relatively high; 4. Cannot be used as daily body metal monitoring due to time constraints

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