Patent Document

CROSS REFERENCE TO RELATED APPLICATIONS 
     This is a continuation application of U.S. patent application Ser. No. 13/920,093, filed on Jun. 18, 2013, and all benefits of such earlier application are hereby claimed for this new continuation application. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a semiconductor integrated device, and more particularly, to semiconductor integrated device including a Fin Field effect transistor (hereinafter abbreviated as FinFET) device and protecting structures. 
     2. Description of the Prior Art 
     Conventional planar metal-oxide-semiconductor (MOS) transistor has difficulty when scaling down to 65 nm and below. Therefore the non-planar transistor technology such as Fin Field effect transistor (FinFET) technology that allows smaller size and higher performance is developed to replace the planar MOS transistor. 
     The FinFET device is conventionally formed by: First a silicon layer of a substrate is patterned to form fin structures (not shown) by a proper etching process. Then, an insulating layer surrounding lower portions of the fin structures is formed and followed by forming a gate covering a portion of the insulating layer and top portions of the fin structures. Next, dopants are introduced and annealing treatments are performed to form source/drain in the fin structures not covered by the gate. Since the manufacturing processes of the FinFET device are similar to the traditional logic device processes, it provides superior process compatibility. Furthermore, when the FinFET device is formed on the SOI substrate, traditional shallow trench isolation (STI) is no longer in need. More important, since the FinFET device increases the overlapping area between the gate and the fin structures, the channel region is more effectively controlled. This therefore reduces drain-induced barrier lowering (DIBL) effect and short channel effect, and the current between the source and the drain is increased. 
     However, the FinFET device still faces many problems. For example, because the fin structures are long and slim plate-like structures, they are susceptible to physical or electrical impacts. The long and slim fin structures are even damaged upon those impacts. Therefore, a strong and sufficient protecting structure is always in need for the FinFET device. 
     SUMMARY OF THE INVENTION 
     According to an aspect of the present invention, a semiconductor integrated device is provided. The semiconductor integrated device includes a substrate, a plurality of active fins, and a plurality of first protecting fins. The substrate includes at least an active region surrounded by the first protecting fins, and the active fins are positioned in the active region. The active fins and the first protecting fins all extend along a first direction. 
     According to another aspect of the present invention, a semiconductor integrated device is provided. The semiconductor integrated device includes a substrate, a plurality of active fins, and a plurality of protecting fin frames. The substrate includes at least an active region. The active fins are positioned in the active region, and the protecting fin frames surround the active region. 
     According to still another aspect of the present invention, a semiconductor integrated device is provided. The semiconductor integrated device includes a substrate having an active region defined thereon, a plurality of active fins positioned in the active region, and a plurality of first protecting fins surrounding the active region. Each of the plurality of active fins extends along a first direction and includes a first length along the first direction. The plurality of first protecting fins extend along the first direction. One of the plurality of first protecting fins immediately adjacent to the active region has a second length along the first direction, and the second length is longer than the first length. 
     According to the semiconductor integrated device provided by the present invention, the first protecting fins or the protecting fin frames are formed to surround the active region simultaneously with forming the active fins in the active region. By positioning the first protecting fins or the protecting fin frames, the long and slim active fins in the active region are protected from physical or electrical impacts. 
     These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIGS. 1-4  are schematic drawings illustrating a semiconductor integrated device provided by a first preferred embodiment of the present invention, wherein 
         FIG. 2  is a schematic drawing in a step subsequent to  FIG. 1 , 
         FIG. 3  is a schematic drawing in a step subsequent to  FIG. 2 , and 
         FIG. 4  is a schematic drawing in a step subsequent to  FIG. 3 . 
         FIG. 5  is a schematic drawing illustrating a modification to the first preferred embodiment. 
         FIG. 6  is a schematic drawing illustrating a semiconductor integrated device provided by a second preferred embodiment of the present invention. 
         FIG. 7  is a schematic drawing illustrating a modification to the second preferred embodiment. 
         FIGS. 8-9  are schematic drawings illustrating a semiconductor integrated device provided by a third preferred embodiment of the present invention, wherein 
         FIG. 9  is a schematic drawing in a step subsequent to  FIG. 8 . 
         FIG. 10  is a schematic drawing illustrating a modification to the third preferred embodiment. 
         FIG. 11  is a schematic drawing illustrating a semiconductor integrated device provided by a fourth preferred embodiment of the present invention. 
         FIG. 12  is a schematic drawing illustrating a modification to the fourth preferred embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     Please refer to  FIGS. 1-4 , which are schematic drawings illustrating a semiconductor integrated device provided by a first preferred embodiment of the present invention. As shown in  FIG. 1 , a substrate  100  is provided. The substrate  100  can include a silicon-on-insulator (SOI) substrate or a bulk silicon substrate. It is well-known to those skilled in the art that a SOI substrate upwardly includes a silicon substrate, a bottom oxide (BOX) layer and a semiconductor layer such as a single crystalline silicon layer. The substrate  100  includes an active region  102  and a peripheral region  104  defined thereon. As shown in  FIG. 1 , the active region  102  is surrounded by the peripheral region  104 . However, those skilled in the art would easily realize that spatial relationship and sizes of the active region  102  and the peripheral region  104  are only exemplarily shown in  FIG. 1 . In other words, the spatial relationship and sizes of the active region  102  and the peripheral region  104  can be adjusted if required. Furthermore, a hard mask layer (not shown) is formed on the substrate  100 . In the preferred embodiment, the hard mask layer can be a multi-layered structure such as an oxide/nitride/oxide layer, but not limited to this. Please still refer to  FIG. 1 . Then, a plurality of mandrel patterns  110  are formed on the hard mask layer. The mandrel patterns  110  can include polysilicon, but not limited to this. It is noteworthy that some of the mandrel patterns  110  are formed across both of the active region  102  and the peripheral region  104  as shown in  FIG. 1 . 
     Please refer to  FIG. 2 . After forming the mandrel patterns  110  on the substrate  100 , a material layer such as an insulating layer, for example but not limited to, a silicon nitride (SiN) layer (not shown) formed by atomic layer deposition (ALD) or chemical vapor deposition (CVD), is blanketly formed on the substrate  100 . However, those skilled in the art should understand other suitable material of which an etching rate is different from the mandrel patterns  110  can be involved. Next, the material layer is etched back, and thus a plurality of spacer patterns  112  are formed on sidewalls of the mandrel patterns  110 . 
     Please refer to  FIG. 3 . After forming the spacer patterns  112 , an etching process is performed to remove the mandrel patterns  110 . It is noteworthy that, portions of the spacer patterns  112 , particularly the spacer patterns  112  at two respective ends of the mandrel patterns  110  are removed before, during or after the etching process according to the preferred embodiment. More important, the spacer patterns  112  across the active region  102  and the peripheral region  104  are cut before, during or after the etching process to form gaps  114  in those the spacer patterns  112 . As shown in  FIG. 3 , the gaps  114  are formed in the boundary between the active region  102  and the peripheral region  104  for separating the spacer patterns  112  that used to be across the active region  102  and the peripheral region  104 . 
     Please refer to  FIG. 4 . After forming the spacer patterns  112  and the gaps  114 , the hard mask layer is patterned for defining placement and size of fin structures with the spacer patterns  112  serving as masks. Then, the substrate  100  is etched using the patterned hard mask layer as an etching mask. Accordingly, a plurality of fin structures are formed on the substrate  100 . After forming the fin structures, the patterned hard mask can be removed if required. It is noteworthy that the fin structures formed in the active region  102  are formed in a region where the source/drain of the FinFET device to be formed, therefore the fin structures in the active region  102  are taken as active fins  140 . As shown in  FIG. 4 , the active fins  140  extend along a first direction D 1 . It is also noteworthy that, the fin structures formed in the peripheral region  104  serve as a protecting structure for the active fins and/or the FinFET devices in the active region  102 , therefore those fin structures are taken as first protecting fins  142 . As shown in  FIG. 4 , the active region  102  is surrounded by the first protecting fins  142 . Also, the first protecting fins  142  extend along the first direction D 1 . More important, the gaps  114  are transferred into the fin structures from the spacer patterns  112 . Therefore, the active fins  140  and the first protecting fins  142  in the same row are separated and spaced apart from each other by the gaps  114 . In other words, the gaps  114  separate the active fins  140  in the active region  102  from the first protecting fins  142  in the peripheral region  104 , therefore characteristics and practical electrical performance of the active fins  140  and/or the devices is prevented from being influenced by the first protecting fins  142 . After forming the active fins  140  and the first protecting fins  142 , other elements required by FinFET devices are formed in the active region  102 . For example, a gate dielectric layer, agate layer, lightly-doped drains, spacers, and source/drains are sequentially formed and thus at least a FinFET transistor device (not shown) is constructed. Additionally, those skilled in the art would easily realize that process such as metal gate process, selective epitaxial growth (SEG) process, silicide process, inter-layer dielectric formation, contact plug formation, and multi-layer interconnection process can be integrated in the FinFET fabrication if required, and those details are omitted herein in the interest of brevity. 
     Please refer to  FIG. 5 , which is a schematic drawing illustrating a modification to the preferred embodiment. According to the instant modification, a plurality of strengthening structures  150  are formed on the first protecting fins  142  simultaneously with forming the aforementioned elements in the active region  102 . As shown in  FIG. 5 , the strengthening structures  150  can be formed on the first protecting fins  142  simultaneously with forming a gate layer  160  in the active region  102 . Accordingly, the strengthening structures  150  can include semiconductor material such as polysilicon. Those skilled in the art would easily realize that the relationship between the gate layers  160  and the active fins  140  are only exemplarily shown in  FIG. 5 . Each gate layer  160  can be formed across more or less active fins  140  depending on product requirement. Also, Different gate layers  160  can be formed across different active fins  140  if required. Or, the strengthening structures  150  can be formed on the first protecting fins  142  simultaneously with forming metal gates, contact plugs or slot contacts  160  in the active region  102 . Accordingly, the strengthening structures  150  can include metal material. In the same concept, the relationship between the metal gates/contact plugs/slot contacts  160  and the active fins  140  can be modified depending on different product requirements. It is noteworthy that the strengthening structures  150  are perpendicular to the first protecting fins  142  in the substrate-horizontal direction and thus the first protecting fins  142  in different rows are electrically connected to each other by the strengthening structures  150 . Furthermore, an orthogonal grid pattern is obtained as shown in  FIG. 5 , and thus structural strength of the first protecting fins  142  in the peripheral region  104  is improved. Additionally, metal layers can be formed on the strengthening structure  150  in the peripheral region  104  simultaneously with forming metal interconnects in the active region  102 . Those metals layer, which are electrically isolated from the metal interconnects in the active region  102 , are physically and electrically connected to the strengthening structure  150 , and thus the structural strength of the first protecting fins  142  in the peripheral region  104  can be further improved. 
     According to the semiconductor integrated device provided by the preferred embodiment and its modification, the first protecting fins  142  are formed to surround the active region  102  simultaneously with forming the active fins  140  and the strengthening structures  150  are formed to improve the structural strength of the first protecting fins  142 . By providing the first protecting fins  142  and the strengthening structure  150 , a guard ring for providing electrical isolation or a seal ring for providing physical obstruction is formed, and thus the long and slim active fins  142  in the active region  102  are protected from those physical or electrical impacts. Additionally, since the first protecting fins  142  are formed simultaneously with forming the active fins  140  and the strengthening structures  150  are formed simultaneously with forming elements such as gate layer or contact plugs, the protecting structure for rending the required protection to the active fins  140  is provided without increasing process complexity according to the preferred embodiment. 
     Please refer to  FIG. 6 , which is a schematic drawing illustrating a semiconductor integrated device provided by a second preferred embodiment of the present invention. It should be noted that since steps for forming the protecting structure are identical in both of the first and second preferred embodiments, those details are omitted in the interest of brevity. As shown in  FIG. 6 , a substrate  200  is provided. The substrate  200  can include a SOI substrate or a bulk silicon substrate. The substrate  200  includes an active region  202  and a peripheral region  204  defined thereon. As shown in  FIG. 6 , the active region  202  is surrounded by the peripheral region  204 . As mentioned above, those skilled in the art would easily realize that spatial relationship and sizes of the active region  202  and the peripheral region  204  can be adjusted if required. Furthermore, a hard mask layer (not shown) is formed on the substrate  200 . Then, a plurality of mandrel patterns (not shown) are formed on the hard mask layer and followed by forming a plurality of spacer patterns (not shown) on sidewalls of the mandrel patterns. 
     Please refer to  FIG. 6  again. After forming the spacer patterns, an etching process is performed to remove the mandrel patterns. It is noteworthy that, portions of the spacer patterns, particularly the spacer patterns at two respective ends of the mandrel patterns are removed before, during or after the etching process according to the preferred embodiment. More important, the spacer patterns across the active region  202  and the peripheral region  204  are cut before, during or after the etching process to form gaps in those the spacer patterns. The gaps are formed in the boundary between the active region  202  and the peripheral region  204  for separating the spacer patterns that used to be across the active region  202  and the peripheral region  204 . 
     Please still refer to  FIG. 6 . After forming the spacer patterns and the gaps, the hard mask layer is patterned for defining placement and size of fin structures with the spacer patterns serving as masks. Then, the substrate  200  is etched using the patterned hard mask layer as etching mask. Accordingly, a plurality of fin structures are formed on the substrate  200 . After forming the fin structures, the patterned hard mask can be removed if required. As mentioned above, the fin structures formed in the active region  102  are taken as active fins  240 . As shown in  FIG. 6 , the active fins  240  extend along a first direction D 1 . It is also noteworthy that, a plurality of the first protecting fins  242  and a plurality of the second protecting fins  244  are formed in the peripheral region  204  according to the preferred embodiment. The first protecting fins  242  extend along the first direction D 1  and are arranged along a second direction D 2 . The second protecting fins  244  extend along the second direction D 2  and are arranged along the first direction D 1 . The first direction D 1  and the second direction D 2  are different from each other. In the preferred embodiment, the first direction D 1  and the second direction D 2  are perpendicular, but not limited to this. Accordingly, the first protecting fins  242  are positioned at two opposite sides of the active region  202  while the second protecting fins  244  are positioned at another two opposite sides of the active region  202  as shown in  FIG. 6 . In other words, the first protecting fins  242  and the second protecting fins  244  in combination surround the active region  202  for rendering protection. As mentioned above, the gaps are transferred into the fin structures from the spacer patterns. Therefore, the active fins  240  and the first protecting fins  242  in the same row are separated and spaced apart from each other by gaps  214 . Additionally, the active fins  240  and the second protecting fins  244  are separated and spaced apart from each other by another gaps  216 . In other words, the gaps  214 / 216  separate the active fins  240  in the active region  102  from the first protecting fins  242 /the second protecting fins  244  in the peripheral region  204 , therefore characteristics and practical electrical performance of the active fins  240  and/or devices is prevented from being influenced by the first protecting fins  242 /the second protecting fins  244 . After forming the active fins  240 , the first protecting fins  242  and the second protecting fins  244 , other elements required by FinFET devices are formed in the active region  202 . 
     Please refer to  FIG. 7 , which is a schematic drawing illustrating a modification to the preferred embodiment. According to the instant modification, at least a strengthening structure  250  is formed on the first protecting fins  242  and the second protecting fins  244  simultaneously with forming the aforementioned elements in the active region  202 . As shown in  FIG. 7 , the strengthening structure  250  can be formed on the first protecting fins  242  and the second protecting fins  244  simultaneously with forming a gate layer  260  in the active region  202 . Accordingly, the strengthening structure  250  can include semiconductor material such as polysilicon. Those skilled in the art would easily realize that the relationship between the gate layers  260  and the active fins  240  are only exemplarily shown in  FIG. 7 . Each gate layer  260  can be formed across more or less active fins  240  depending on product requirement. Also, Different gate layers  260  can be formed across different active fins  240  if required. Or, the strengthening structure  250  can be formed on the first protecting fins  242  and the second protecting fins  244  simultaneously with forming metal gates, contact plugs or slot contacts  260  in the active region  202 . Accordingly, the strengthening structure  250  can include metal material. In the same concept, the relationship between the metal gates/contact plugs/slot contacts  260  and the active fins  240  can be modified depending on different product requirements. It is noteworthy that the strengthening structure  250  is perpendicular to both of the first protecting fins  242  and the second protecting fins  244  in the substrate-horizontal direction, and thus the first protecting fins  242  and the second protecting fins  244  are all electrically connected to each other by the strengthening structure  250 . Accordingly, structural strength of the first protecting fins  242  and the second protecting fins  244  in the peripheral region  204  is improved. Additionally, metal layers can be formed on the strengthening structure  250  in the peripheral region  204  simultaneously with forming metal interconnects in the active region  202 . Those metals layer, which are electrically isolated from the metal interconnects in the active region  202 , are physically and electrically connected to the strengthening structure  250 , and thus the structural strength of the first protecting fins  242  and the second protecting fins  244  in the peripheral region  204  can be further improved. 
     According to the semiconductor integrated device provided by the preferred embodiment and its modification, the first protecting fins  242  and the second protecting fins  244  are formed to surround the active region  202  simultaneously with forming the active fins  240  and the strengthening structure  250  is formed to improve the structural strength of the first protecting fins  242  and the second protecting fins  244 . By providing the first protecting fins  242 , the second protecting fins  244 , and the strengthening structure  250 , a guard ring for providing electrical isolation or a seal ring for providing physical obstruction is formed, and thus the long and slim active fins  242  in the active region  202  are protected from those physical or electrical impacts. As mentioned above, since the first protecting fins  242  and the second protecting fins  244  are formed simultaneously with forming the active fins  240  and the strengthening structure  250  is formed simultaneously with forming elements such as gate layer or contact plugs, the protecting structure for rending the required protection to the active fins  240  is provided without increasing process complexity according to the preferred embodiment. 
     Please refer to  FIGS. 8-9 , which are schematic drawings illustrating a semiconductor integrated device provided by a third preferred embodiment of the present invention. As shown in  FIG. 8 , a substrate  300  is provided. The substrate  300  includes an active region  302  and a peripheral region  304  defined thereon. As shown in  FIG. 8 , the active region  302  is surrounded by the peripheral region  304 . As mentioned above, those skilled in the art would easily realize that spatial relationship and sizes of the active region  302  and the peripheral region  304  can be adjusted if required. Furthermore, a hard mask layer (not shown) is formed on the substrate  300 . Then, a plurality of mandrel patterns  310   a / 310   b  are formed on hard mask layer. The mandrel patterns  310   a / 310   b  can include polysilicon, but not limited to this. It is noteworthy that the mandrel patterns  310   a  in the active region  302  are different from the mandrel patterns  310   b  in the peripheral region  304  according to the preferred embodiment: The mandrel patterns  310   a  in the active region  302  are formed according to product requirements, however the mandrel patterns  310   b  in the peripheral region  304  are formed to have a frame shape for surrounding and sealing the active region  302 . 
     Please refer to  FIG. 9 . After forming the mandrel patterns  310   a / 310   b  on the substrate  300 , a material layer having an etching rate different from the mandrel patterns  310   a / 310   b  under the same etching recipe is blanketly formed on the substrate  300 . Next, the material layer is etched back, and thus a plurality of spacer patterns (not shown) is formed on sidewalls of the mandrel patterns  310   a / 310   b . After forming the spacer patterns, an etching process is performed to remove the mandrel patterns  310   a / 310   b . It is noteworthy that, portions of the spacer patterns, particularly the spacer patterns at two respective ends of the mandrel patterns  310   a  in the active region  302  are removed before, during or after the etching process according to the preferred embodiment. Next, the hard mask layer is patterned for defining placement and size of fin structures with the spacer patterns serving as masks. Then, the substrate  300  is etched using the patterned hard mask layer as etching mask. Accordingly, a plurality of fin structures is formed on the substrate  300 . After forming the fin structures, the patterned hard mask can be removed if required. It is noteworthy that the fin structures formed in the active region  302  are taken as active fins  340 . As shown in  FIG. 9 , the active fins  340  extend along a first direction D 1 . It is also noteworthy that, the fin structures formed in the peripheral region  304  serve as a protecting structure for the active fins  340  and/or the FinFET devices in the active region  302 , and the fin structures obtain the frame shape inherently from the mandrel pattern  310   b , therefore those fin structures are taken as protecting fin frames  342 . And the protecting fin frames  342  are all concentric. As shown in  FIG. 9 , the active region  302  is surrounded and sealed by the protecting fin frames  342 . Additionally, the protecting fin frames  342  are physically and electrically isolated from the active fins  340 , therefore characteristics and practical electrical performance of the active fins  340  and/or devices is prevented from being influenced by the protecting fin frames  342 . After forming the active fins  340  and the protecting fin frames  342 , other elements required by FinFET devices are formed in the active region  302 . 
     Please refer to  FIG. 10 , which is a schematic drawing illustrating a modification to the preferred embodiment. According to the instant modification, a plurality of strengthening structures  350  is formed on the protecting fin frames  342  simultaneously with forming the aforementioned elements in the active region  302 . As shown in  FIG. 10 , the strengthening structures  350  can be formed on the protecting fin frames  342  simultaneously with forming agate layer  360  in the active region  302 . Accordingly, the strengthening structures  350  can include semiconductor material such as polysilicon. Those skilled in the art would easily realize that the relationship between the gate layer  360  and the active fins  340  are only exemplarily shown in  FIG. 10 . Each gate layer  360  can be formed across more or less active fins depending on product requirement. Also, Different gate layer  360  can be formed across different active fins  340  if required. Or, the strengthening structures  350  can be formed on the protecting fin frames  342  simultaneously with forming metal gates, contact plugs or slot contacts  360  in the active region  302 . Accordingly, the strengthening structures  350  can include metal material. In the same concept, the relationship between the metal gates/contact plugs/slot contacts  360  and the active fins  36  can be modified depending on different product requirement. It is noteworthy that the strengthening structures  350  are perpendicular to any part of the protecting fin frames  342  in the substrate-horizontal direction, and thus the concentric protecting fin frames  342  are all electrically connected to each other by the strengthening structures  350 . Accordingly, structural strength of the protecting fin frames  342  in the peripheral region  304  is improved. Additionally, metal layers can be formed on the strengthening structures  350  in the peripheral region  304  simultaneously with forming metal interconnects in the active region  302 . Those metals layer, which are electrically isolated from the metal interconnects in the active region  302 , are physically and electrically connected to the strengthening structures  350 , and thus the structural strength of the protecting fin frames  342  in the peripheral region  304  can be further improved. 
     According to the semiconductor integrated device provided by the preferred embodiment and its modification, the protecting fin frames  342  are formed to surround and seal the active region  302  simultaneously with forming the active fins  340  and the strengthening structures  350  are formed to improve the structural strength of the protecting fin frames  342 . By providing the protecting fin frames  342  and the strengthening structures  350 , a guard ring for providing electrical isolation or a seal ring for providing physical obstruction is formed, and thus the long and slim active fins  342  in the active region  302  are protected from those physical or electrical impacts. Additionally, since the protecting fin frames  342  are formed simultaneously with forming the active fins  340  and the strengthening structures  350  are formed simultaneously with forming elements such as gate layer or contact plugs, the protecting structure for rending the required protection to the active fins  340  is provided without increasing process complexity according to the preferred embodiment. 
     Please refer to  FIG. 11 , which is a schematic drawing illustrating a semiconductor integrated device provided by a fourth preferred embodiment of the present invention. It should be noted that since steps for forming the protecting structure are identical in both of the third and fourth preferred embodiments, those details are omitted in the interest of brevity. As shown in  FIG. 11 , a substrate  400  is provided. The substrate  400  can include a SOI substrate or a bulk silicon substrate. The substrate  400  includes an active region  402  and a peripheral region  404  defined thereon. As shown in  FIG. 11 , the active region  402  is surrounded by the peripheral region  404 . As mentioned above, those skilled in the art would easily realize that spatial relationship and sizes of the active region  402  and the peripheral region  404  can be adjusted if required. Furthermore, a hard mask layer (not shown) is formed on the substrate  400 . Then, a plurality of mandrel patterns (not shown) is formed on the hard mask layer. It is noteworthy that the mandrel patterns in the active region  402  are different from the mandrel patterns in the peripheral region  404  according to the preferred embodiment: The mandrel patterns in the active region  402  are formed according to product requirements, however the mandrel patterns in the peripheral region  404  are formed to have a frame shape for surrounding and sealing the active region  402 . 
     Please still refer to  FIG. 11 . After forming the mandrel patterns on the substrate  400 , a plurality of spacer patterns (not shown) is formed on sidewalls of the mandrel patterns and followed by performing an etching process to remove the mandrel patterns. It is noteworthy that, portions of the spacer patterns, particularly the spacer patterns at two respective ends of the mandrel patterns in the active region  402 , and particularly at least a spacer pattern in the peripheral region  404  are removed before, during or after the etching process according to the preferred embodiment. Next, the hard mask layer is patterned for defining placement and size of fin structures with the spacer patterns serving as masks. Then, the substrate  400  is etched using the patterned hard mask layer as etching mask. Accordingly, a plurality of fin structures is formed on the substrate  400 . After forming the fin structures, the patterned hard mask can be removed if required. 
     It is noteworthy that the fin structures formed in the active region  402  are taken as active fins  440 . As shown in  FIG. 11 , the active fins  440  extend along a first direction D 1 . It is also noteworthy that, the fin structures formed in the peripheral region  404  serve as a protecting structure for the active fins and/or the FinFET devices in the active region  402 , and the fin structures obtain the frame shape inherently from the mandrel pattern, therefore those fin structures are taken as protecting fin frames  442 . And the protecting fin frames  442  are all concentric. As shown in  FIG. 11 , the active region  402  is surrounded and sealed by the protecting fin frames  442 . Additionally, the protecting fin frames  442  are physically and electrically isolated from the active fins  440 , therefore characteristics and practical electrical performance of the active fins  440  and/or devices is prevented from being influenced by the protecting fin frames  442 . More important, each of the protecting fin frames  442  further includes a plurality of gaps  444  formed therein except the innermost protecting fin frame  442   a  according to the preferred embodiment. As shown in  FIG. 11 , the gaps  444  are formed to interrupt each protecting fin frame  442  and corresponding to sidewalls of two adjacent protecting fin frames  442 . Consequently, a labyrinth pattern is obtained as shown in  FIG. 11 . After forming the active fins  440  and the protecting fin frames  442 , other elements required by FinFET devices are formed in the active region  402 . 
     Please refer to  FIG. 12 , which is a schematic drawing illustrating a modification to the preferred embodiment. According to the instant modification, a plurality of strengthening structures  450  is formed in the protecting fin frames  442  simultaneously with forming the aforementioned elements in the active region  402 . As shown in  FIG. 12 , the strengthening structures  450  can be formed on the protecting fin frames  442  simultaneously with forming agate layer  460  in the active region  402 . Accordingly, the strengthening structures  450  can include semiconductor material such as polysilicon. Those skilled in the art would easily realize that the relationship between the gate layer  460  and the active fins  440  are only exemplarily shown in  FIG. 12 . Each gate layer  460  can be formed across more or less active fins depending on product requirement. Also, Different gate layer  460  can be formed across different active fins  440  if required. Or, the strengthening structures  450  can be formed on the protecting fin frames  442  simultaneously with forming metal gates, contact plugs or slot contacts  460  in the active region  402 . Accordingly, the strengthening structures  450  can include metal material. In the same concept, the relationship between the metal gates/contact plugs/slot contacts  460  and the active fins  440  can be modified depending on different product requirement. It is noteworthy that the strengthening structures  450  are formed to fill up the gaps  444  in each protecting fin frame  442 . Furthermore, the concentric protecting fin frames  442  can be all electrically connected to each other by filling the gaps  444  with the strengthening structures  450  much larger than the gaps  444 . Accordingly, structural strength of the protecting fin frames  442  in the peripheral region  404  is improved. Additionally, metal layers can be formed on the strengthening structures  450  in the peripheral region  404  simultaneously with forming metal interconnects in the active region  402 . Those metals layer, which are electrically isolated from the metal interconnects in the active region  402 , are connected to the strengthening structures  450 , and thus the structural strength of the protecting fin frames  442  in the peripheral region  404  can be further improved. 
     According to the semiconductor integrated device provided by the preferred embodiment and its modification, the protecting fin frames  442  are formed to surround and seal the active region  402  simultaneously with forming the active fins  440  and the strengthening structures  450  are formed to improve the structural strength of the protecting fin frames  442 . By providing the protecting fin frames  442  and the strengthening structures  450 , a guard ring for providing electrical isolation or a seal ring for providing physical obstruction is formed, and thus the long and slim active fins  442  in the active region  402  are protected from those physical or electrical impacts. Additionally, since the protecting fin frames  442  are formed simultaneously with forming the active fins  440  and the strengthening structures  350  are formed simultaneously with forming elements such as gate layer or contact plugs, the protecting structure for rending the required protection to the active fins  440  is provided without increasing process complexity according to the preferred embodiment. 
     Accordingly, the semiconductor integrated device provided by the present invention includes the first protecting fins or the protecting fin frames formed to surround the active region simultaneously with forming the active fins in the active region. By positioning the first protecting fins or the protecting fin frames, guard ring for providing electrical isolation or a seal ring for providing physical obstruction is formed. In other words, by providing the first protecting fins or the protecting fin frames, the long and slim the active fins in the active region are protected from those physical or electrical impacts. 
     Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.

Technology Category: 5