Mohammad T Chowdhury

US Patent:

20140004685, Jan 2, 2014

Filed:

Jun 13, 2013

Appl. No.:

13/917568

Inventors:

Mohammad Kamruzzaman CHOWDHURY - Santa Clara CA, US
Wei-Sheng Lei - San Jose CA, US
Todd Egan - Fremont CA, US
Brad Eaton - Menlo Park CA, US
Madhava Rao Yalamanchili - Morgan Hill CA, US
Ajay Kumar - Cupertino CA, US

International Classification:

H01L 21/78
B23K 26/36
H01L 21/67

US Classification:

438463, 392416, 21912169

Abstract:

Laser and plasma etch wafer dicing using UV-curable adhesive films. A mask is formed covering ICs formed on the wafer, as well as any bumps providing an interface to the ICs. The semiconductor wafer is coupled to a carrier substrate by a double-sided UV-curable adhesive film. The mask is patterned by laser scribing to provide a patterned mask with gaps. The patterning exposes regions of the semiconductor wafer, below thin film layers from which the ICs are formed. The semiconductor wafer is then etched through the gaps in the patterned mask to singulate the ICs. The UV-curable adhesive film is partially cured by UV irradiation through the carrier. The singulated ICs are then detached from the partially cured adhesive film still attached to the carrier substrate, for example individually by a pick and place machine. The UV-curable adhesive film may then be further cured for the film's complete removal from the carrier substrate.

US Patent:

20140017879, Jan 16, 2014

Filed:

Jun 13, 2013

Appl. No.:

13/917366

Inventors:

Mohammad Kamruzzaman Chowdhury - Santa Clara CA, US
Wei-Sheng Lei - San Jose CA, US
Todd Egan - Fremont CA, US
Brad Eaton - Menlo Park CA, US
Madhava Rao Yalamanchili - Morgan Hill CA, US
Ajay Kumar - Cupertino CA, US

International Classification:

H01L 21/78

US Classification:

438462, 1563451, 15634555

Abstract:

Uniform masking for wafer dicing using laser and plasma etch is described. In an example, a method of dicing a semiconductor wafer having a plurality of integrated circuits having bumps or pillars includes uniformly spinning on a mask above the semiconductor wafer, the mask composed of a layer covering and protecting the integrated circuits. The mask is then patterned with a laser scribing process to provide a patterned mask with gaps, exposing regions of the semiconductor wafer between the integrated circuits. The semiconductor wafer is then etched through the gaps in the patterned mask to singulate the integrated circuits.

US Patent:

20130280890, Oct 24, 2013

Filed:

Mar 20, 2013

Appl. No.:

13/847964

Inventors:

Wei-Sheng Lei - San Jose CA, US
Mohammad K. Chowdhury - Santa Clara CA, US
Todd Egan - Fremont CA, US
Brad Eaton - Menlo Park CA, US
Madhava Rao Yalamanchili - Morgan Hill CA, US
Ajay Kumar - Cupertino CA, US

International Classification:

H01L 21/78
H01L 21/67

US Classification:

438463, 1563451

Abstract:

Laser and plasma etch wafer dicing using UV-curable adhesive films is described. In an example, a method includes forming a mask above the semiconductor wafer. The semiconductor wafer is coupled to a carrier substrate by a UV-curable adhesive film. The mask covers and protects the integrated circuits. The mask is patterned with a laser scribing process to provide a patterned mask with gaps. The patterning exposes regions of the semiconductor wafer between the integrated circuits. The semiconductor wafer is then etched through the gaps in the patterned mask to form singulated integrated circuits. The UV-curable adhesive film is then irradiated with ultra-violet (UV) light. The singulated integrated circuits are then detached from the carrier substrate.

US Patent:

20160365283, Dec 15, 2016

Filed:

Jun 12, 2015

Appl. No.:

14/738389

Inventors:

Wei-Sheng Lei - San Jose CA, US
Mohammad Kamruzzaman Chowdhury - Santa Clara CA, US
Brad Eaton - Menlo Park CA, US
Ajay Kumar - Cupertino CA, US

International Classification:

H01L 21/82
H01L 21/308
H01J 37/32
H01L 21/02
H01L 21/67
H01L 21/3065
H01L 21/268

Abstract:

Methods of dicing semiconductor wafers, each wafer having a plurality of integrated circuits, are described. In an example, a method of dicing a semiconductor wafer including a plurality of integrated circuits includes forming a water soluble mask above the semiconductor wafer, the water soluble mask covering and protecting the integrated circuits. The method also includes baking the water soluble mask to increase the etch resistance of the water soluble mask. The method also includes, subsequent to baking the water soluble mask, patterning the water soluble mask with a laser scribing process to provide a water soluble patterned mask with gaps, exposing regions of the semiconductor wafer between the integrated circuits. The method also includes plasma etching the semiconductor wafer through the gaps in the water soluble patterned mask to singulate the integrated circuits.

US Patent:

20160035577, Feb 4, 2016

Filed:

Mar 11, 2014

Appl. No.:

14/775651

Inventors:

- Santa Clara CA, US
Mohammad Kamruzzaman CHOWDHURY - Santa Clara CA, US
Todd EGAN - Fremont CA, US
Brad EATON - Menlo Park CA, US
Madhava Rao YALAMANCHILI - Morgan Hill CA, US
Ajay KUMAR - Cupertino CA, US

International Classification:

H01L 21/308
H01L 21/3065
H01L 21/687
B23K 26/402
H01L 21/67
H01L 21/673
H01L 21/82
B23K 26/364

Abstract:

Methods of dicing substrates having a plurality of ICs. A method includes forming a multi-layered mask comprising a laser energy absorbing, non-photodefinable topcoat disposed over a water-soluble base layer disposed over the semiconductor substrate. Because the laser light absorbing material layer is non-photodefinable, material costs associated with conventional photo resist formulations may be avoided. The mask is direct-write patterned with a laser scribing process to provide a patterned mask with gaps. The patterning exposes regions of the substrate between the ICs. Absorption of the mask layer within the laser emission band (e.g., UV band and/or green band) promotes good scribe line quality. The substrate may then be plasma etched through the gaps in the patterned mask to singulate the IC with the mask protecting the ICs during the plasma etch. The soluble base layer of the mask may then be dissolved subsequent to singulation, facilitating removal of the layer.

US Patent:

20150122419, May 7, 2015

Filed:

Jan 12, 2015

Appl. No.:

14/595120

Inventors:

Mohammad Kamruzzaman Chowdhury - Santa Clara CA, US
Wei-Sheng Lei - San Jose CA, US
Todd Egan - Fremont CA, US
Brad Eaton - Menlo Park CA, US
Madhava Rao Yalamanchili - Morgan Hill CA, US
Ajay Kumar - Cupertino CA, US

International Classification:

H01L 21/67
B23K 26/36
B23K 26/40
H01L 21/683

US Classification:

1563453

Abstract:

Laser and plasma etch wafer dicing using UV-curable adhesive films. A mask is formed covering ICs formed on the wafer, as well as any bumps providing an interface to the ICs. The semiconductor wafer is coupled to a carrier substrate by a double-sided UV-curable adhesive film. The mask is patterned by laser scribing to provide a patterned mask with gaps. The patterning exposes regions of the semiconductor wafer, below thin film layers from which the ICs are formed. The semiconductor wafer is then etched through the gaps in the patterned mask to singulate the ICs. The UV-curable adhesive film is partially cured by UV irradiation through the carrier. The singulated ICs are then detached from the partially cured adhesive film still attached to the carrier substrate, for example individually by a pick and place machine. The UV-curable adhesive film may then be further cured for the film's complete removal from the carrier substrate.

US Patent:

20140106542, Apr 17, 2014

Filed:

Oct 11, 2013

Appl. No.:

14/052085

Inventors:

Mohammad Kamruzzaman CHOWDHURY - Santa Clara CA, US
Wei-Sheng Lei - San Jose CA, US
Todd Egan - Fremont CA, US
Brad Eaton - Menlo Park CA, US
Madhava Rao Yalamanchili - Morgan Hill CA, US
Ajay Kumar - Cupertino CA, US

International Classification:

H01L 21/82
H01L 21/67

US Classification:

438462, 1563453

Abstract:

Methods and systems of laser and plasma etch wafer dicing using UV-curable adhesive films. A method includes forming a mask covering ICs formed on the wafer. The semiconductor wafer is coupled to a film frame by a UV-curable adhesive film. A pre-cure of the UV-curable adhesive film cures a peripheral portion of the adhesive extending beyond an edge of the wafer to improve the exposed adhesive material's resistance to plasma etch and reduce hydrocarbon redeposition within the etch chamber. The mask is patterned by laser scribing to provide a patterned mask with gaps. The patterning exposes regions of the semiconductor wafer, below thin film layers from which the ICs are formed. The semiconductor wafer is plasma etched through the gaps in the patterned mask to singulate the ICs. A center portion of the UV-curable adhesive is then cured and the singulated ICs detached from the film.