CN102479679A - Treatment method of silicon slag on back of epitaxial silicon wafer - Google Patents

Abstract

The invention discloses a treatment method of silicon slag on the back of an epitaxial silicon wafer. The method comprises the following steps: 1) a clean wafer box, a wafer with wide chamfers and a special dust collector for the clean room are prepared; 2) the epitaxial silicon wafer is placed in the wafer box, the state of the silicon slag on the back of the epitaxial silicon wafer is observed under an accent light lamp to determine the region of the silicon slag; 3) the special dust collector for the clean room is started and directed at the back of the epitaxial silicon wafer to be treated, then the silicon slag is scratched off from the silicon wafer prepared in the step 1); and 4) after scratching one region, the other regions with silicon slag are scratched until all the silicon slag is scratched off, and the epitaxial silicon wafer is cleaned. The method disclosed by the invention is simple and practical, the required equipment is conventional laboratory equipment; most of silicon slag on the back of the treated epitaxial silicon wafer is scratched off, thus the problem that the epitaxial silicon wafer can not be sucked by a mask aligner can be solved; and the prepared photoetching strip is uniform in width and the photoetching yield of the epitaxial silicon wafer is increased.

Description

The processing method of silicon epitaxial wafer back side white residue

Technical field

The present invention relates to semi-conducting material clean technical field, particularly the processing method of silicon epitaxial wafer back side white residue.

Background technology

Silicon is a kind of very important semi-conducting material, can be used for making components and parts such as diode, triode, luminescent device, pressure cell, solar cell.Processing of a siliceous semiconductor components and devices often needs the complicated technology program to accomplish, and comprising at the silicon chip growing epitaxial layers, forms silicon epitaxial wafer.

Behind the large-diameter silicon wafer growing epitaxial layers, in the marginal growth of silicon chip back the white residue that do not wait of area, cause the outer silicon chip of delaying to be placed on the mask aligner after, can't form efficient vacuum, inhale incessantly silicon epitaxial wafer; Perhaps the white residue place evenness at the silicon epitaxial wafer back side is relatively poor, causes the photoetching bar wide inhomogeneous and silicon epitaxial wafer was lost efficacy; And existing testing flatness appearance is when test silicon epitaxial wafer evenness; Adopt equally spaced three pillars to be configured on the same circumference than the little 6.35mm of silicon epitaxial wafer nominal diameter; And therefore the white residue or coarse the appearing at mostly in the scope of edge 3～5mm of general silicon epitaxial wafer dorsal edge can't detect the difference of evenness with above-mentioned instrument.

At present, also do not have effective way to remove the white residue at the silicon epitaxial wafer back side that has produced, make it can satisfy its follow-up technological requirement; Silicon epitaxial wafer for influencing subsequent technique has normally been scrapped in vain, not only increases environmental pressure, and causes the significant wastage of physical resources and human resources.

Summary of the invention

The technical problem that the present invention will solve provides a kind of processing method of simply, effectively removing silicon epitaxial wafer back side white residue.

For solving the problems of the technologies described above, the technical scheme that the present invention taked is to carry out according to following step:

1. prepare clean film magazine, wide bevel edge the special-purpose dust catcher of silicon chip and Clean room;

2. silicon epitaxial wafer is placed in the above-mentioned film magazine, is not less than the state of observing the white residue at the said silicon epitaxial wafer back side under the major light of 200klx in lamp illumination, confirm the zone of white residue;

3. open the special-purpose dust catcher of Clean room and aim at the back side of pending silicon epitaxial wafer, the hand-held then 1. described silicon chip of step is scraped the white residue of step described in 2.;

4. after having scraped a zone, scrape the zone that other have white residue, after having scraped fully, clean silicon epitaxial wafer.

The present invention adopt wide bevel edge silicon chip scrape white residue, on the one hand can not bring other contamination; The silicon chip edge of the opposing party's face width bevel edge is sharp, is easy to scrape the white residue at the silicon epitaxial wafer back side.

Adopt the beneficial effect that technique scheme produced to be: simple, the required equipment of method of the present invention is conventional laboratory equipment; The white residue major part at the silicon epitaxial wafer back side after the processing is wiped off by silicon chip and is siphoned away by dust catcher; Solve mask aligner and inhaled the incessantly problem of silicon epitaxial wafer; And prepared photoetching bar width is even, has improved the photoetching rate of finished products of silicon epitaxial wafer, and has practiced thrift a large amount of resources.

Embodiment

1. prepare a clean film magazine, a wide bevel edge silicon chip and the special-purpose dust catcher of Clean room.

2. silicon epitaxial wafer is placed in the above-mentioned film magazine, is not less than the state of observing the white residue at the said silicon epitaxial wafer back side under the major light of 200klx in lamp illumination, confirm the zone of white residue.

At first, the white residue state at elder generation rough observation silicon epitaxial wafer back side under major light;

Then, hold the back side of above-mentioned silicon epitaxial wafer, under major light, examine the back side of silicon epitaxial wafer, confirm that which position white residue is the heaviest with vacuum WAND;

Above-mentioned silicon epitaxial wafer is placed in the film magazine, the heaviest zone of white residue up again.

3. open the special-purpose dust catcher of Clean room and aim at the back side of pending silicon epitaxial wafer, the hand-held then 1. described silicon chip of step is scraped the white residue of step described in 2.; Hand-held for ease, said silicon chip is got 1/4～1/8 size of complete silicon chip, and with wide bevel edge as the face of scraping white residue; When scraping white residue, be 50～70 ° angle of inclination between said silicon chip and the silicon epitaxial wafer.

In this step, if at first scrape white residue, and then open dust catcher, the granule that is scraped off can be attracted to the positive edge of silicon epitaxial wafer, in follow-up cleaning, can't remove.

Wherein said dust catcher outlet is 10～50mm apart from the silicon epitaxial wafer back side, and the maintenance dust catcher can not be too big apart from the spacing of silicon epitaxial wafer in whole process, otherwise the white residue granule that is scraped off can be drawn onto the front edge of silicon epitaxial wafer, and cleaning can't be removed; Above-mentioned spacing also should not be too little, otherwise be prone to run into silicon epitaxial wafer and cause contamination.

4. after having scraped a zone, scrape the zone that other have white residue, after having scraped fully, clean silicon epitaxial wafer.

Adopt the present invention, effectively removed the white residue at the silicon epitaxial wafer back side, even make the very serious silicon epitaxial wafer of white residue still can satisfy the processing technology of subsequent handling; The present invention has solved the white residue problem that always can't thoroughly solve through adopting simple method, and the silicon epitaxial wafer that should scrap before making is able to use, and has practiced thrift ample resources.

Claims (2)

1. the white residue processing method at a silicon epitaxial wafer back side is characterized in that carrying out according to following step:

1. prepare clean film magazine, wide bevel edge the special-purpose dust catcher of silicon chip and Clean room;

2. silicon epitaxial wafer is placed in the above-mentioned film magazine, is not less than the state of observing the white residue at the said silicon epitaxial wafer back side under the major light of 200klx in lamp illumination, confirm the zone of white residue;

3. open the special-purpose dust catcher of Clean room and aim at the back side of pending silicon epitaxial wafer, the hand-held then 1. described silicon chip of step is scraped the white residue of step described in 2.;

4. after having scraped a zone, scrape the zone that other have white residue, after having scraped fully, clean silicon epitaxial wafer.

2. the white residue processing method at the silicon epitaxial wafer according to claim 1 back side is characterized in that said dust catcher exports apart from the silicon epitaxial wafer back side 10～50mm.