Abstract:
A process applied to grinding, dicing, and/or stacking semiconductors is disclosed. One of its features is that after transparent material is stuck on its active surface, a semiconductor is ground from another surface thereof to become thinner, then take advantage of transparency of the transparent material to cut the transparent material and the semiconductor, to obtain at least one smaller semiconductor unit such as die or chip. Another feature is that the transparent material remains sticking to the active surface of the die by an adhesion layer until the die is attached to a carrier or another die, and then the transparent material and the adhesion layer are removed by taking advantage of a function of the adhesion layer: receiving a ray to lose adhesion between it and the active surface. Preferably the ray reaches the adhesion layer via the transparent material stuck on the active surface of the die.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This is a continuation-in-part of prior, pending application Ser. No. 11/319,110, filed Dec. 27, 2005, which claims priority to Taiwan Application No. 093141194, filed Dec. 29, 2004. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to grinding and/or dividing semiconductor, particularly to attaching and/or stacking at least one ground and/or divided semiconductor onto a device carrier, and specifically relates to attaching and/or stacking a wafer onto a device carrier after grinding and/or dividing the wafer. 
     BACKGROUND OF THE INVENTION 
     It is a trend for IC or semiconductor industries to minimize the size of components. For example, each of multiple chips to be stacked conventionally according to U.S. Pat. No. 5,793,108 must be thinned to a thickness of 2˜4 mils. 
     Conventional processes for thinning a chip, such as those disclosed in U.S. Pat. Nos. 6,527,627, 6,159,071, include typical steps as shown in  FIGS. 1   a - 1   f . In  FIG. 1   a , tape  3  is stuck onto the front surface  2  (the surface with bonding pad  6  thereon) of wafer  1 , so that the back surface  4  of wafer  1  may be ground by grinding machine  30  (as shown in  FIG. 1   b ) to have a thinner wafer  11  (as shown in  FIG. 1   c ). Subsequently a frame  5  to be used in dividing wafer is stuck onto the back surface  14  of thinner wafer  11  (as shown in  FIG. 1   d ), and the tape  3  on the front surface  2  of thinner wafer  11  is removed thereafter (as shown in  FIG. 1   e ) so that thinner wafer  11  can be divided (or diced) by sawing machine  40  (as shown in  FIG. 1   f ). 
     Thinner wafer  11 , obtained by grinding according to the conventional processes as described above, is always subjected to warpage (as shown in  FIG. 2 ) due to stress residue resulting from grinding, bringing difficulty and trouble for subsequent steps, leading to vulnerability to crack of thinner wafer  11 . Furthermore, the chip or die  21  (as shown in  FIG. 3 ) obtained from dividing thinner wafer  11 , being so thin, always tends to be subjected to crack  8  when picked up (e.g. picked up by a pick-up head  50  as shown in  FIG. 3 ) during the process of Die Bond in which the chip (or die)  21  is moved to substrate (as shown in  FIG. 4 ). The chip (or die)  21  is also subjected to crack  8  even when it is placed on substrate  7  (also can be seen from  FIG. 4 ). 
     In order to solve the poor quality problem resulting from thinner wafer, U.S. Pat. No. 6,264,535 disclosed a technology as shown in  FIGS. 5   a - 5   e . Referring to  FIGS. 5   a - 5   e  (based on the technology according to U.S. Pat. No. 6,264,535), after front surface  2  of wafer  1  is sawn (by sawing machine  40 ) to have recesses  9  (not sawn to bottom), tape  3  is stuck onto front surface  2 , and back surface  4  of wafer  1  is ground by grinding machine  30 , thereby a group of separated dice  21  are obtained, and frame  12  is then stuck onto back surface  4  of dice  21 , subsequently tape  3  is removed from the front surface of the dice  21 . Although the process according to U.S. Pat. No. 6,264,535 may likely more or less ease the problem of wafer crack resulting from thinning a wafer, it is subject to much complication (e.g. plural times of sticking tape and frame, etc), and incurs higher cost, not to mention that it is not for solving the problem of crack of thinner die inherent in the die bonding process thereafter. Further reference is made now with respect to JP patent 2003059871 which is for solving similar problem. 
     According to JP patent 2003059871, a reinforced thin film is stuck to the tape used in grinding a wafer, and the thin film is reinforced by a support layer made of thermo-softening resin with specific storage elasticity. Although the reinforced structure according to JP patent 2003059871 might more or less provide some usefulness in resolving the problem, it requires using specific material, resulting in higher cost and more complication. Still further reference is made now with respect to JP patent 11265928 which is for solving similar problem. According to JP patent 11265928, a wafer to be polished is stuck onto a surface of a specific plate, where the coarseness of the surface is controlled to be in a specific range. The technology according to JP patent 11265928, even if useful, to some extent, for solving the problem inherent in thinning a wafer, is not necessarily helpful to the reduction of process difficulty and product failure rate in the steps following the process of thinning a wafer. 
     In view of the fact no ideal solution has ever come up, the present invention not only develops a process for related industries to eliminate or reduce negative effect and/or product failure rate resulting from thinning (e.g. grinding) and/or dividing a wafer, but also provides efficacy of simplification and benefit of lowering cost for the process following thinning and/or dividing a wafer. 
     Difference Between the Present Invention and Prior Arts 
     One of the main features of the present invention is the dividing step in which a semiconductor (such as a wafer) with transparent material thereon is divided, by taking advantage of transparency of the transparent material, into dice each with the transparent material thereon. The dividing step includes: cutting the transparent material ( 64  in  FIG. 6   f  of the present application) which is on the active surface ( 61  in  FIG. 6   f  of the present application) of the wafer, to reach the active surface of the wafer, and cutting the wafer from the active surface to obtain at least a die which has transparent material remaining on its active surface ( 67  in  FIG. 6   f  of the present application). For example, the transparent material is cut according to a division line on the active surface of the wafer, so that the division line is reached after the transparent material is cut, and the wafer is then cut according to the division line or from the division line to obtain a die. It is by the transparency of transparent material that the wafer with transparent material on its active surface can be cut into dice each with transparent material remaining on the active surface thereof. The dividing step is done after thinning the wafer which has had the transparent material stuck on the active surface thereof. 
     No prior arts have ever been known which has the same feature as or similar feature to the dividing step of the present invention. Some prior arts are cited as follows to highlight the unique feature of the present invention. All the reference figures and reference numbers mentioned below in regard to these prior arts are not shown in the present application, but shown in their U.S. patent application/Issue Publication. 
     According to US Patent Application 20070015342 (specifically  FIGS. 16-18  thereof), protective tape  2  ( FIG. 16  thereof) on the active surface of a wafer is peeled off before cutting the wafer into dice ( FIG. 18  thereof). The dividing step according to US Patent Application 20070015342 includes: peeling off the protective tape  2  ( FIG. 16  thereof) from the active surface of a wafer, and cutting the wafer from the active surface to obtain dice. In contrast, according to the present invention, the transparent material ( 64  in  FIG. 6   f  of the present application) on the active surface ( 61  in  FIG. 6   f  of the present application) of a wafer, together with the wafer, are cut into dice ( 66  in  FIG. 6   f  of the present application) each with part of the transparent material remaining on the active surface thereof, i.e., the dividing step according to the present invention includes: first cutting (instead of peeling off) the transparent material on the active surface of a wafer, to reach the active surface (specifically, to reach a division line on the active surface) of the wafer, and then cutting the wafer from the active surface (specifically, from the division line on the active surface) to obtain at least a die ( 66  in  FIGS. 6   f - 6   g  of the present application). After the dividing step according to the present invention, the transparent material remains on the active surface of the obtained die, providing convenience for processing the obtained die. For example, the transparent material remaining on the obtained die can significantly reduce the chance that the obtained die is hurt when moving it to a carrier. 
     It is obvious now that there can be no protective tape on the active surface of each die obtained from dividing a wafer into dice according to US Patent Application 20070015342, and each die (specifically the active surface thereof) has no material (such as the transparent material according to the present invention) for its protection when it is processed (e.g. when the obtained die is moved to a wiring substrate  91  as shown in  FIG. 20  of the US publication of the prior art). The significant difference between the present invention and US Patent Application 20070015342, results from the fact that the present invention makes use of transparency of the transparent material stuck on the active surface of a wafer, thereby the wafer can be cut into dice without need of taking off the transparent material beforehand. In contrast, prior art US Patent Application 20070015342 has to peel off protective tape from a wafer before cutting the wafer into dice. 
     According to US Patent Application 20070179127 (specifically  FIGS. 3A-3F  thereof), after grinding a wafer from its inactive surface to reach the bottom of grooves  33 , the wafer has been divided into dice each adhering to adhesive layer  23  which adheres to protection tape  34 , each of the dice is then moved up to separate it from the protection tape  34 , and adhesive layer  23  is torn off and cut off. In contrast, according to the present invention, after the process of grinding a wafer, the transparent material on the active surface of the wafer is cut to reach the active surface (specifically to reach a division line on the active surface), and then the wafer is cut from its active surface (specifically from a division line on the active surface) to obtain dice, i.e., the dividing step according to the present invention includes: first cutting the transparent material ( 64  in  FIG. 6   f  of the present application) which is on the active surface ( 61  in  FIG. 6   f  of the present application) of a wafer, to reach the active surface (specifically to reach a division line on the active surface) of the wafer, and then cutting the wafer from the active surface (specifically from the division line on the active surface) to obtain dice ( 66  in  FIGS. 6   f - 6   g  of the present application). The contrast stated above results in the fact that the die obtained from cutting a wafer according to the present invention has transparent material remaining between the active surface thereof and an open space, while the die obtained from cutting a wafer according to the prior art (US Patent Application 20070179127) has adhesive layer and/or protection tape remaining between the active surface thereof and a backholder  36 . One feature (transparent material remaining between an open space and the active surface of a die obtained from cutting a wafer) of the present invention provides benefit for processing the die (e.g. for minimizing the chance of hurting the die when moving it to a carrier). The benefit provided by the present invention originates from using transparent material and making use of transparency of the transparent material, which is unique in contrast with known prior arts. 
     According to U.S. Pat. No. 6,264,535 (admitted prior art shown by  FIGS. 5   a - 5   e  of the present application), after grinding a wafer  1  from its inactive surface  4 , the wafer  1  has been divided into dice  21  with active surface adhering to tape  3 , the tape  3  is then peeled off to obtain dice each separated from another as shown in  FIG. 5   e  of the present invention. In contrast, according to the present invention, after grinding a wafer, the transparent material ( 64  in  FIG. 6   f  of the present application) on the active surface ( 61  in  FIG. 6   f  of the present application) of a wafer, together with the wafer, are cut into dice ( 66  in  FIG. 6   f  of the present application) each with part of the transparent material remaining on the active surface thereof and separate from another part (the part of transparent material which is on the active surface of another one of the dice), i.e., the dividing step according to the present invention includes: first cutting the transparent material on the active surface of a wafer, to reach the active surface (specifically, to reach a division line on the active surface) of the wafer, and then cutting the wafer from the active surface (specifically, from the division line on the active surface) to obtain dice ( 66  in  FIGS. 6   f - 6   g  of the present application). After cutting a wafer into dice according to the present invention, each die is adhered by one part of transparent material which is on its active surface and is separated from another die, thereby each of the dice can be processed separately and with minimized chance of getting hurt. For example, each of the dice can be moved separately to a carrier with minimized chance of getting hurt. 
     At least one of the main features of the present invention, which results from using transparent material and making use of transparency of the transparent material, is unique as can be seen from foregoing explanations. Not only one but also the other features of the present invention shall be deemed unique in contrast to prior arts, as will be seen from the following descriptions. 
     SUMMARY OF THE INVENTION 
     An object of the present invention is to eliminate or reduce negative effect incurred on the quality of semiconductor product by the process of thinning a semiconductor. 
     Another object of the present invention is to eliminate or reduce negative effect incurred on the quality of semiconductor product by the process of dividing a semiconductor. 
     A further object of the present invention is to eliminate or reduce product failure rate in the process (e.g. Die Bonding, Die Stacking) following thinning and/or dividing a semiconductor. 
     Another further object of the present invention is to provide efficacy of simplification and benefit of lowering cost for the process following thinning and/or dividing a wafer. 
     The process provided according to the present invention is for applying to a semiconductor including an active surface and an inactive surface, wherein the distance between the active surface and the inactive surface defines an initial thickness of the semiconductor. One aspect of the process comprises: sticking transparent material (e.g. glass, plastic, etc) to the active surface of the semiconductor; grinding the semiconductor from the inactive surface thereof to obtain a new inactive surface of the semiconductor, with the distance between the new inactive surface and the active surface smaller than the initial thickness (e.g. equal to a desired die thickness); and applying a dividing step to the semiconductor via the transparent material (e.g. using a means such as a knife or a sawing machine or an energy beam, to first cut the transparent material and then cut the semiconductor after the means reaches the active surface of the semiconductor) to obtain at least a first die, wherein the first die includes an active surface and an inactive surface, the active surface of the first die is part of the active surface of the semiconductor, the inactive surface of the first die is part of the new inactive surface of the semiconductor, and the active surface of the first die has at least part of the transparent material thereon. An example of the aforementioned energy beam is laser. 
     One way to stick the transparent material to the active surface of the semiconductor, is that one type of sticking material is spread between the transparent material and the active surface of the semiconductor, i.e., the transparent material and/or the active surface of the semiconductor are/is coated with one type of sticking material, wherein the sticking material is so characterized as to lose capability of sticking to the active surface of the semiconductor when receiving one type of light (e.g. ultraviolet light). By means of transparency of the transparent material, it is assured the type of light can easily reach the sticking material which is between the transparent material and the active surface of the semiconductor, i.e., the type of light can easily reach the sticking material which is between the transparent material and the active surface of the first die, thereby the type of light makes the sticking material lose capability of sticking to the active surface of the semiconductor, i.e., the type of light makes the sticking material lose capability of sticking to the active surface of the first die, thus the transparent material and the sticking material can be easily removed from the first die. For example, moving the first die together with the transparent material onto a device carrier, with the inactive surface of the first die sticking to the device carrier, the type of light can pass the transparent material to reach the sticking material, and make the sticking material lose the capability of sticking to the active surface of the first die, thereby the transparent material and the sticking material can be conveniently removed from the first die, with the first die still on (sticking to) the device carrier. 
     The sticking material according to the present invention preferably includes a first glue layer, a second glue layer, and a film layer, wherein the first glue layer contacts the transparent material, the second glue layer contacts the active surface of the semiconductor, the film layer is between the first glue layer and the second glue layer, both the film layer and the first glue layer are capable of letting the type of light pass therethrough; the second glue layer, in response to the type of light, makes the sticking material lose capability of sticking to the active surface of the semiconductor. For example, the second glue layer is UV glue (ultraviolet-ray glue), and the type of light is ultraviolet ray. 
     The dividing step according to the present invention preferably comprises: recognizing via the transparent material at least a line on the active surface of the semiconductor; and dividing the transparent material and the semiconductor according to the line. 
     If the transparent material according to the present invention is a type of hard material, it can be better for supporting or carrying thin die, thus significantly avoiding the crack of thin die. 
     The number of die/dice obtained from the dividing step according to the present invention, is not limited to one, and may be more than one. For better description, let another one among the obtained plural dice called “second die”. Obviously the second die also includes an active surface and an inactive surface, wherein the active surface of the second die is part of the active surface of the semiconductor, the inactive surface of the second die is part of the new inactive surface of the semiconductor, and the active surface of the second die also has at least part of the transparent material thereon. Thus the process according to the present invention may further comprise: obtaining at least a second die by the dividing step, the second die including an active surface and an inactive surface, the active surface of the second die being part of the active surface of the semiconductor, the inactive surface of the second die being part of the new inactive surface of the semiconductor, the active surface of the second die having at least part of the transparent material thereon; stacking the second die to the first die, i.e., sticking the inactive surface of the second die to the active surface of the first die (to form a stack of two or more dice); letting the type of light pass the transparent material to reach the sticking material which is between the transparent material and the second die, thereby making the sticking material lose the capability of sticking to the second die; and removing the transparent material and the sticking material from the second die. 
     The process may preferably further comprise: before connecting the first die to the device carrier, spreading an adhesive onto at least one selected from between a surface of the device carrier and the inactive surface of the first die, i.e., coating a surface of the device carrier and/or the inactive surface of the first die with an adhesive; and before stacking the second die to the first die, spreading an adhesive onto at least one part selected from between the inactive surface of the second die and the active surface of the first die, i.e., coating the inactive surface of the second die and/or the active surface of the first die with an adhesive. The adhesive used in the process includes at least one type of material selected from between silver paste, nonconductive paste, and B-stage paste, i.e., the adhesive includes silver paste and/or nonconductive paste and/or B-stage paste. 
     According to the process provided by the present invention, in case the adhesive is B-stage paste, heat is necessary for raising the temperature of the B-stage paste, thereby making the B-stage paste have adhesion capability. Preferably, before heat is applied to the B-stage paste, the first die is stuck to the device carrier via the B-stage paste, and the inactive surface of the second die is stuck to the active surface of the first die via the B-stage paste. 
     Another aspect of the process provided according to the present invention comprises: sticking transparent material to an active surface of a semiconductor; grinding the semiconductor from an inactive surface of the semiconductor to obtain a new inactive surface of the semiconductor, the distance between the new inactive surface and the active surface being smaller than an initial thickness of the semiconductor or equal to a desired die thickness; coating the new inactive surface of the semiconductor with B-stage paste; applying a dividing step to the semiconductor via the transparent material to obtain a first die (or smaller semiconductor, or plural dice, or smaller chips), wherein the first die includes an active surface and an inactive surface, the active surface of the first die is part of the active surface of the semiconductor, the inactive surface of the first die is part of the new inactive surface of the semiconductor, the active surface of the first die has at least part of the transparent material thereon, and the inactive surface of the first die has at least part of the B-stage paste thereon; placing the first die together with the transparent material on a device carrier, with the inactive surface of the first die connecting the device carrier via the B-stage paste; providing heat to raise the temperature of the B-stage paste, so that the B-stage paste becomes capable of sticking the inactive surface of the first die to the device carrier; letting the type of light pass the transparent material to reach the sticking material, so that the sticking material loses capability of sticking to the active surface of the first die; and removing the transparent material and the sticking material from the first die. 
     As the number of die/dice obtained from the dividing step is not limited to one, the above process may further comprise: obtaining at least a second die by the dividing step, wherein the second die includes an active surface and an inactive surface, the active surface of the second die is part of the active surface of the semiconductor, the inactive surface of the second die is part of the new inactive surface of the semiconductor, the active surface of the second die has at least part of the transparent material thereon, and the inactive surface of the second die has at least part of the B-stage paste thereon; before providing heat to raise the temperature of the B-stage paste on the inactive surface of the first die, letting the inactive surface of the second die connect the active surface of the first die via the B-stage paste; letting the type of light pass the transparent material to reach the sticking material which is between the transparent material and the second die, so that the sticking material loses capability of sticking to the active surface of the second die; and removing the transparent material and the sticking material from the second die. The step of letting the inactive surface of the second die connect the active surface of the first die via the B-stage paste, is not necessarily before providing heat to raise the temperature of the B-stage paste on the inactive surface of the first die. But in case the step of letting the inactive surface of the second die connect the active surface of the first die via the B-stage paste is not before providing heat to raise the temperature of the B-stage paste on the inactive surface of the first die, a second time of providing heat is necessary for raising the temperature of the B-stage paste on the inactive surface of the second die. 
     As long as the image of the semiconductor (specifically the image of a division line on the active surface of the semiconductor) appearing via the transparent material can be recognized, the transparent material and the semiconductor can be divided (or diced) according to the image of the semiconductor (specifically the image of a division line on the active surface of the semiconductor) seen from the transparent material, to obtain a smaller semiconductor having at least part of the transparent material and at least part of the sticking material thereon. Accordingly a further aspect of the process provided by the present invention comprises: 
     sticking transparent material to an active surface of a semiconductor via one type of sticking material; grinding the semiconductor from an inactive surface thereof to obtain a new inactive surface of the semiconductor, the distance between the new inactive surface and the active surface of the semiconductor being smaller than an initial thickness of the semiconductor; dividing the transparent material and the semiconductor according to the image of the semiconductor seen from the transparent material, to obtain a smaller semiconductor (e.g. die or chip) having at least part of the transparent material and at least part of the sticking material thereon, i.e., to obtain a smaller semiconductor which is part of the semiconductor but separated from the semiconductor, and which still has at least part of the transparent material and at least part of the sticking material thereon. To remove the transparent material and the sticking material from the smaller semiconductor, apply one type of light to the sticking material which is on the smaller semiconductor, to make the sticking material lose capability of sticking to the smaller semiconductor, thereby the transparent material and the sticking material can be easily separated from the smaller semiconductor. The type of light is applied to the sticking material preferably via the transparent material, and the sticking material either is itself a glue layer or includes a glue layer, wherein the glue layer is characterized by losing capability of sticking to the active surface of the smaller semiconductor in response to receiving the type of light. The glue layer is preferably made of UV glue (ultraviolet-ray glue), and the type of light is preferably ultraviolet ray. 
     The present invention may best be understood through the following description with reference to the accompanying drawings, in which: 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIGS. 1   a - 1   f  show the steps disclosed according to prior arts. 
         FIGS. 2-4  show some aspects of prior arts to be improved. 
         FIGS. 5   a - 5   e  show another prior art. 
         FIGS. 6   a - 6   h  show a process representing an embodiment provided according to the present invention. 
         FIGS. 7   a - 7   c  show some steps provided according to the present invention, and following the process described by  FIGS. 6   a - 6   h.    
         FIGS. 8   a - 8   c  show a process representing an embodiment provided according to the present invention for stacking plural dice or chips. 
         FIG. 9  shows a structure representing an embodiment of the sticking material used in the process provided according to the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       FIGS. 6   a - 6   h  show an embodiment representing a first aspect of the process provided according to the present invention. The process is for applying to a semiconductor  60  including an active surface  61  and an inactive surface  62 , wherein the distance between the active surface  61  and the inactive surface  62  defines an initial thickness  63  of the semiconductor. The process comprises: sticking transparent material  64  (e.g. glass, plastic, etc) to the active surface  61  of the semiconductor  60 ; grinding (e.g. using a grinding machine  30  to grind) the semiconductor  60  from the inactive surface  62  to obtain a new inactive surface  65  of the semiconductor  60 , with the distance  70  between the new inactive surface  65  and the active surface  61  smaller than the initial thickness  63 , i.e., the semiconductor  60  becomes thinner; and applying a dividing step to the semiconductor  60  via the transparent material  64 , e.g. applying a sawing machine  40  or another type of means to first cut the transparent material  64  towards the active surface  61 , and then (when or after the sawing machine  40  or another means reaches the active surface  61  of the semiconductor  60 ) cut the semiconductor  60  to obtain at least a first die  66  or smaller semiconductor (e.g. chip or plural dice or plural chips), wherein the first die  66  includes an active surface  67  and an inactive surface  68 , the active surface  67  of the first die  66  is part of the active surface  61  of the semiconductor, the inactive surface  68  of the first die  66  is part of the new inactive surface  65  of the semiconductor  60 , and the active surface  67  of the first die  66  has at least part of the transparent material  64  thereon, i.e., there is part of transparent material  64  still sticking to the active surface  67  of the first die  66 . Preferably, the semiconductor  60  is placed on a grinding supporter (not shown in figures) before being ground, and placed on a sawing supporter  73  before being divided (or diced). 
     One way to cut the transparent material  64  and the semiconductor  60  is by recognizing a division line (not shown in figures) or a plurality of division lines (not shown in figures) on the active surface  61  of the semiconductor  60 , cutting the transparent material  64  toward the division line(s), and cutting the semiconductor  60  according to the division line(s) after the means  40  (sawing machine, or knife, or energy beam) reaches the division line(s). For example, the semiconductor  60  is cut from the division line(s) to obtain dice  66  each with part of the transparent material  64  on its active surface  67 . 
     One way to stick the transparent material  64  to the active surface  61  of the semiconductor  60 , is that one type of sticking material  69  is spread between the transparent material  64  and the active surface  61  of the semiconductor  60 , or that the transparent material  64  and/or the active surface  61  of the semiconductor  60  are/is coated with sticking material  69 , wherein the sticking material  69  is so characterized as to lose capability of sticking to the active surface  61  when receiving one type of light (e.g. ultraviolet light). Taking advantage of transparency of the transparent material  64 , it is assured the type of light can easily reach the sticking material  69  which is between the transparent material  64  and the active surface  61  of the semiconductor  60  (i.e., between the transparent material  64  and the active surface  67  of the first die  66 ), thereby make the sticking material  69  lose capability of sticking to the active surface  61  of the semiconductor  60  (i.e., lose capability of sticking to the active surface  67  of the first die  66 ), thus the transparent material  64  and the sticking material  69  can be easily removed from the first die  66 . An example of moving die  66  together with transparent material  64  and the sticking material  69  is shown in  FIG. 6   g . According to  FIG. 6   g , a pick-up head  74  is used to move the first die  66  together with the transparent material  64  onto a device carrier  71  (provided as shown in  FIG. 6   h ), with the inactive surface  68  of the first die  66  connecting (or sticking to) a certain portion of the device carrier  71  (e.g. the first die  66  connecting a surface  76  or part of the surface  76  of device carrier  71 ), the type of light  72  (as shown in  FIG. 7   a ) is applied to sticking material  69  (by means of transparency of the transparent material  64 , light  72  can easily pass transparent material  64  to reach the sticking material  69 ), and sticking material  69  is turned to lose capability of sticking to the active surface  67  of the first die  66 , thus the transparent material  64  and the sticking material  69  can be conveniently removed from the first die  66 , with the first die  66  still on (or sticking to) the device carrier  71 . 
     One way of connecting the first die  66  to the device carrier  71 , is to coat surface  76  (or a certain portion of surface  76 ) of device carrier  71  and/or inactive surface  68  of first die  66  with an adhesive  75  (e.g. silver paste, or nonconductive paste, or B-stage paste), as shown in  FIGS. 6   h ,  7   a , and  7   b . In case adhesive  75  is B-stage paste, heat must be provided to raise the temperature of the B-stage paste, in order to let the B-stage paste capable of providing adhesion. 
     In the process according to  FIGS. 7   a - 7   c , plural dice  66  (or chips) obtained from the steps of thinning and dividing semiconductor  60  (as described in  FIGS. 6   a - 6   h ), are attached to (e.g. with inactive surface stuck to) device carrier  71 ; and ultraviolet rays  72  are applied to sticking material  69  via transparent material  64 , to make sticking material  69  lose capability of sticking to active surface  67  of each first die  66 ; a pick-up head  74  is then used to remove transparent material  64  and sticking material  69  from each first die  66 . 
       FIG. 8   a  shows a step of stacking plural dice (or chips). In the step according to  FIG. 8   a , the first die  66  (or chip) obtained from the steps of thinning and dividing semiconductor  60  (described in  FIGS. 6   a - 6   h ), is attached to (e.g. with its inactive surface stuck to) device carrier  71 ; and a second die  86  (or chip) also obtained from the steps as described in  FIGS. 6   a - 6   h , is attached to (e.g. with its inactive surface of second die  86  stuck to) active surface  67  of first die  66  (it must be noted both the transparent material  64  and sticking material  69  have been removed from first die  66 , as can be seen from  FIG. 7   b  or  7   c ). The second die  86  also includes an active surface  67  and an inactive surface  68 , wherein the active surface  67  of the second die  86  is part of the active surface  61  of the semiconductor  60  (as can be seen from  FIGS. 6   a - 6   f ), the inactive surface  68  of the second die  86  is part of the new inactive surface  65  of the semiconductor  60  (also as can be seen from  FIGS. 6   a - 6   f ), and the active surface  67  of the second die  86  also has at least part of the transparent material  64  thereon (again also can be seen from  FIGS. 6   a - 6   f ). 
     The second die  86  according to  FIG. 8   a  is stuck to the active surface  67  of first die  66  by using an adhesive  85  (e.g. silver paste, or nonconductive paste, or B-stage paste), i.e., before second die  86  is attached to the active surface  67  of first die  66 , active surface  67  of first die  66  and/or inactive surface  68  of second die  86  are/is coated with adhesive  85 . As long as second die  86  can be stuck to first die  66 , only part of active surface  67  of first die  66  and/or part of inactive surface  68  of second die  86  need/needs to be coated with adhesive  85 . In case adhesive  85  is the same as adhesive  75 , i.e., is B-stage paste, heat must be provided to raise the temperature of adhesive  85 , in order to let the adhesive  85  capable of providing adhesion. 
     What is shown in  FIG. 8   b  results from the step as shown in  FIG. 8   a . According to  FIG. 8   b , ultraviolet rays  77 , analogue with light  72  as shown in  FIG. 7   a , are applied to sticking material  69  (i.e., applied to the material  69  sticking to active surface  67  of second die  86 ) via transparent material  64 , in order to make sticking material  69  lose capability of sticking to active surface  67  of second die  86 . A pick-up head  74 , as shown in  FIG. 8   c , is then used to remove transparent material  64  and sticking material  69  from second die  86  (i.e., from active surface  67  of second die  86 ). 
     Alternatively, in the process provided according to the present invention, if the new inactive surface  65  ( 65  is shown in  FIG. 6   d , but  75  and  85  not) is coated with adhesive  75  (or  85 ) right after semiconductor  60  is thinned (e.g. after semiconductor  60  is ground by grinding machine  30 , as shown in  FIG. 6   d ) but before semiconductor  60  is divided, then the inactive surface  68  of each of the plural dice or chips (such as first die  66  in  FIG. 6   f  and second die  86  in  FIG. 8   a ) obtained from dividing semiconductor  60 , will otherwise all have adhesive  75  (or  85 ) thereon, thereby the inactive surface  68  of first die  66  can be stuck to device carrier  71  by means of adhesive  75  (or  85 ), and the inactive surface  68  of second die  86  can be stuck to the active surface  67  of first die  66  also by means of adhesive  75  (or  85 ), as shown in  FIG. 8   c.    
     Both adhesive  75  and adhesive  85  shown in  FIGS. 8   a - 8   c  may include silver paste and/or nonconductive paste and/or B-stage paste. If adhesive  75  and adhesive  85  are B-stage paste or include B-stage paste, heat must be provided to raise their temperature after first die  66  is attached to device carrier  71  and second die  86  is attached to first die  66 . The heat is to make adhesive  75  and adhesive  85  capable of providing adhesion. 
     An embodiment of sticking material  69  is shown in  FIG. 9 . The sticking material  69  according to  FIG. 9  is a slice of ultraviolet film (UV film) including a first glue layer  81 , a second glue layer  82 , and a film layer  83 , wherein the first glue layer  81  contacts the transparent material  64 , the second glue layer  82  contacts the active surface of the semiconductor (e.g. active surface  61  of semiconductor  60 , active surface  67  of first die  66  and second die  86 ), the film layer  83  is between the first glue layer  81  and the second glue layer  82 , both the film layer  83  and the first glue layer  81  are capable of letting one type of light (e.g. ultraviolet ray) pass therethrough; the second glue layer  82  is made of ultraviolet paste (UV paste) which, in response to ultraviolet light applied thereto, will lose capability of providing adhesion. For example, when receiving ultraviolet rays  92 , the second glue layer  82  loses capability of providing adhesion, i.e., when ultraviolet rays  92  reach second glue layer  82 , the second glue layer  82  loses capability of providing adhesion, and the sticking material  69  loses capability of sticking to the active surface of the semiconductor (e.g. active surface  67  of first die  66  or second die  86 , or active surface  61  of semiconductor  60 ), thereby the transparent material  64  and the sticking material  69  can be easily removed from the active surface (e.g. active surface  67  of first die  66  or second die  86 , or active surface  61  of semiconductor  60 ). Preferably the ultraviolet rays  92  reach second glue layer  82  by passing transparent material  64 , first glue layer  81 , and the film layer  83 . 
     While the invention has been described in terms of what are presently considered to be the most practical or preferred embodiments, it shall be understood that the invention is not limited to the disclosed embodiment. On the contrary, any modifications or similar arrangements shall be deemed covered by the spirit of the present invention.