US5904546A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for dicing semiconductor wafers
Assignee: Micron Technology Inc
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Filing: 1996-02-12
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Granted: 1999-05-18
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Expires: 2016-02-12
Abstract
Abstract A method and apparatus for dicing semiconductor wafers is provided. The method comprises: forming an etch mask on the wafer, and then etching the wafer with a wet etchant, such as KOH, to form a peripheral groove around each die. Etching the wafer can be from the front side of the wafer, from the back side of the wafer or with partial etches from both sides. The etch process can be performed on a single wafer using a spray head apparatus or on batches of wafers using a recirculating dip tank apparatus.
Inventors
- 👤 Alan G. Wood
- 👤 Warren M. Farnworth
- 👤 Salman Akram
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 22:06
CPC Classifications
H; H10; H10P; H10P54/00
Claims Analysis
Total Claims: 29
Claim 1
Independent Claim
128 words
A method for dicing a semiconductor wafer comprising a plurality of semiconductor dice, said method comprising: forming a first mask on a front side of the wafer, the first mask comprising a first layer covering and protecting the dice; forming a second mask on a back side of the wafer, second mask comprising a second layer having a pattern of etch openings to the back side; and following forming of the first mask and the second mask, etching the wafer through the etch openings using a wet etchant to form a peripheral groove around each of the dice, the groove extending from the back side to the front side of the wafer and the first mask providing an etch stop and protecting the dice during the etching step.
Claim 2
Independent Claim
128 words
A method for dicing a semiconductor wafer comprising a plurality of semiconductor dice, said method comprising: forming a first mask on a front side of the wafer, the first mask comprising a first layer covering and protecting the dice; forming a second mask on a back side of the wafer, second mask comprising a second layer having a pattern of etch openings to the back side; and following forming of the first mask and the second mask, etching the wafer through the etch openings using a wet etchant to form a peripheral groove around each of the dice, the groove extending from the back side to the front side of the wafer and the first mask providing an etch stop and protecting the dice during the etching step.
Claim 3
Dependent Claim
23 words
The method of claim 1 wherein forming the first mask comprises blanket positing a layer of Si 3 N 4 on the wafer.
Claim 4
Dependent Claim
20 words
The method of claim 1 wherein the etching step comprises dipping the wafer in a tank containing the wet etchant.
Claim 5
Dependent Claim
17 words
The method of claim 1 wherein the etching step comprises spraying the wet etchant on the wafer.
Claim 6
Dependent Claim
23 words
The method of claim 1 wherein the etch openings have a criss cross pattern that matches a pattern of streets on the wafer.
Claim 7
Dependent Claim
13 words
The method of claim 1 wherein the second mask comprises a hard mask.
Claim 8
Independent Claim
125 words
A method for dicing a semiconductor wafer comprising a plurality of semiconductor dice, said method comprising: forming a protective mask on a first side of the wafer, the protective mask comprising a blanket deposited layer covering the dice; forming an etch mask on a second side of the wafer, the etch mask including a pattern of etch openings to the second side; etching the wafer through the etch openings to the protective mask to form a peripheral groove around each die extending from the second side to the first side of the wafer, with the protective mask providing an etch stop and a support structure for the dice during the etching step; and stripping the etch mask and the protective mask to separate the dice.
Claim 9
Independent Claim
125 words
A method for dicing a semiconductor wafer comprising a plurality of semiconductor dice, said method comprising: forming a protective mask on a first side of the wafer, the protective mask comprising a blanket deposited layer covering the dice; forming an etch mask on a second side of the wafer, the etch mask including a pattern of etch openings to the second side; etching the wafer through the etch openings to the protective mask to form a peripheral groove around each die extending from the second side to the first side of the wafer, with the protective mask providing an etch stop and a support structure for the dice during the etching step; and stripping the etch mask and the protective mask to separate the dice.
Claim 10
Dependent Claim
13 words
The method of claim 7 wherein the protective mask comprises a hard mask.
Claim 11
Dependent Claim
23 words
The method of claim 7 wherein the etch openings are formed in a criss cross pattern corresponding to streets formed on the wafer.
Claim 12
Dependent Claim
18 words
The method of claim 7 further comprising supporting the wafer on a supporting substrate during the etching step.
Claim 13
Dependent Claim
18 words
The method of claim 7 wherein the etching step comprises an anisotropic etch performed with a wet etchant.
Claim 14
Dependent Claim
20 words
The method of claim 7 wherein the etching step comprises dipping the wafer in a tank containing the wet etchant.
Claim 15
Dependent Claim
17 words
The method of claim 7 wherein the etching step comprises spraying the wet etchant at the wafer.
Claim 16
Independent Claim
180 words
A method for dicing a semiconductor wafer comprising a plurality of semiconductor dice, said method comprising: forming a protective mask on a front side of the wafer, the protective mask comprising a blanket deposited layer covering the dice; forming an etch mask on a back side of the wafer, the etch mask including a pattern of etch openings to the back side; placing the front side of the wafer on a supporting substrate; with the wafer on the supporting substrate, etching the wafer through the etch openings by spraying or dipping in a wet etchant to form a peripheral groove around each die extending from the back side to the front side of the wafer, the protective mask providing an etch stop and protecting the dice during the etching step; removing the wafer from the supporting substrate with the protective mask supporting the dice; stripping the etch mask and placing the back side of the wafer on a second supporting substrate; and stripping the protective mask to separate the dice while the dice remain supported by the second supporting substrate.
Claim 17
Independent Claim
180 words
A method for dicing a semiconductor wafer comprising a plurality of semiconductor dice, said method comprising: forming a protective mask on a front side of the wafer, the protective mask comprising a blanket deposited layer covering the dice; forming an etch mask on a back side of the wafer, the etch mask including a pattern of etch openings to the back side; placing the front side of the wafer on a supporting substrate; with the wafer on the supporting substrate, etching the wafer through the etch openings by spraying or dipping in a wet etchant to form a peripheral groove around each die extending from the back side to the front side of the wafer, the protective mask providing an etch stop and protecting the dice during the etching step; removing the wafer from the supporting substrate with the protective mask supporting the dice; stripping the etch mask and placing the back side of the wafer on a second supporting substrate; and stripping the protective mask to separate the dice while the dice remain supported by the second supporting substrate.
Claim 18
Dependent Claim
27 words
The method of claim 14 further comprising controlling a size and shape of the grooves using the etch openings and selected etch parameters during the etching step.
Claim 19
Dependent Claim
11 words
The method of claim 14 wherein the wet etchant comprises KOH.
Claim 20
Dependent Claim
12 words
The method of claim 14 wherein the protective mask comprises a nitride.
Claim 21
Dependent Claim
12 words
The method of claim 14 wherein the protective mask comprises silicon nitride.
Claim 22
Dependent Claim
22 words
The method of claim 14 wherein the etching step comprises dipping a plurality of wafers into a tank containing the wet etchant.
Claim 23
Dependent Claim
23 words
The method of claim 14 wherein the supporting substrate and the second supporting substrate comprise an elastomeric material stretched over a film frame.
Claim 24
Independent Claim
175 words
A method for dicing a semiconductor wafer comprising a plurality of semiconductor dice, said method comprising: forming a first etch mask on a first side of the wafer, the first etch mask comprising a layer covering the dice and having a first pattern of etch openings; forming a second etch mask on a second side of the wafer, the second etch mask comprising a second pattern of etch openings; etching the wafer through the first pattern of etch openings to form a pattern of grooves extending partially through a thickness of the wafer; following etching, removing the first etch mask and forming a protective layer on the first side of the wafer covering the dice; following forming of the protective layer, attaching the first side of the wafer with the protective layer thereon to a supporting substrate; following attaching, etching the wafer through the second pattern of etch openings to extend the pattern of grooves completely through the thickness of the wafer; and stripping the first and the second etch mask to separate the dice.
Claim 25
Independent Claim
175 words
A method for dicing a semiconductor wafer comprising a plurality of semiconductor dice, said method comprising: forming a first etch mask on a first side of the wafer, the first etch mask comprising a layer covering the dice and having a first pattern of etch openings; forming a second etch mask on a second side of the wafer, the second etch mask comprising a second pattern of etch openings; etching the wafer through the first pattern of etch openings to form a pattern of grooves extending partially through a thickness of the wafer; following etching, removing the first etch mask and forming a protective layer on the first side of the wafer covering the dice; following forming of the protective layer, attaching the first side of the wafer with the protective layer thereon to a supporting substrate; following attaching, etching the wafer through the second pattern of etch openings to extend the pattern of grooves completely through the thickness of the wafer; and stripping the first and the second etch mask to separate the dice.
Claim 26
Dependent Claim
17 words
The method of claim 21 wherein the first etch mask and the second etch mask comprise resist.
Claim 27
Dependent Claim
15 words
The method of claim 21 further comprising performing the attaching step using an adhesive layer.
Claim 28
Dependent Claim
17 words
The method of claim 21 wherein the etching steps comprise dipping the wafer in a wet etchant.
Claim 29
Dependent Claim
17 words
The method of claim 21 wherein the etching steps comprise spraying a wet etchant on the wafer.
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 2002-05-17 | 2002-11-16 | 2003-05-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-05-17 | 2006-11-16 | 2007-05-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-05-17 | 2010-11-16 | 2011-05-18 | $7700.00 | Window Closed / Lapsed |