Stacked spiral inductor

Abstract

A stacked spiral inductor, comprising: a substrate, and multiple stacked insulating layers and inductive metal layers formed on the substrate by means of a semiconductor process. Each inductive metal layer comprises a conductive coil in a shape of a spiral and a through hole area used for connecting two adjacent inductive metal layers. The conductive coils of the inductive metal layers have a common coil center. In two adjacent inductive metal layers, the conductive coil of the lower inductive metal layer is retracted toward the coil center with respect to the conductive coil of the upper inductive metal layer.

1 . A stacked spiral inductor, comprising: a substrate, and multiple stacked insulating layers and inductive metal layers formed on the substrate via a semiconductor process;
 wherein an inductive metal layer comprises a conductive coil in a shape of a spiral, and a through hole area configured to connect two adjacent inductive metal layers, and the conductive coils of the inductive metal layers have a common coil center; and   wherein in two adjacent inductive metal layers, a conductive coil of a lower inductive metal layer is retracted towards the coil center with respect to a conductive coil of an upper inductive metal layer.   
     
     
         2 . The stacked spiral inductor of  claim 1 , wherein retracted distances of the conductive coils of the inductive metal layers are equal to each other, or the retracted distances of the conductive coils of the inductive metal layers form an arithmetic progression. 
     
     
         3 . The stacked spiral inductor of  claim 1 , wherein a retracted distance of each conductive coil of the inductive metal layers ranges from 2 μm to 3 μm. 
     
     
         4 . The stacked spiral inductor of  claim 1 , wherein the conductive coil of each inductive metal layer comprises a lead end and an opening end opposite to the lead end;
 an inductive metal layer located on a top is a first inductive metal layer, an inductive metal layer arranged adjacent to the first inductive metal layer is a second inductive metal layer, and an inductive metal layer adjacent to and below the second inductive metal layer is a third inductive metal layer;   a through hole area in the first inductive metal layer configured to connect with the second inductive metal layer is arranged at the opening end of the first inductive metal layer, and the lead end of the first inductive metal layer is a lead terminal of the spiral inductor; and   a through hole area in the second inductive metal layer configured to connect with the third inductive metal layer is arranged at the same side as the lead end of the first inductive metal layer.   
     
     
         5 . The stacked spiral inductor of  claim 4 , wherein the opening end comprises a first extending portion and a second extending portion that are arranged oppositely and spaced from each other, and the through hole area is arranged at ends of the first extending portion and the second extending portion respectively. 
     
     
         6 . The stacked spiral inductor of  claim 5 , wherein a sum of line widths of the first extending portion and the second extending portion is less than a line width of the conductive coil. 
     
     
         7 . The stacked spiral inductor of  claim 1 , wherein a line width of the conductive coil ranges from 6 μm to 15 μm. 
     
     
         8 . The stacked spiral inductor of  claim 1 , wherein the conductive coil has a shape of a hexagon, an octagon, a quadrangle, or a circle. 
     
     
         9 . The stacked spiral inductor of  claim 1  further comprising a patterned ground shield arranged between the substrate and a bottommost inductive metal layer. 
     
     
         10 . The stacked spiral inductor of  claim 9 , wherein the patterned ground shield is provided with a plurality of concentric metal rings, and each metal ring is provided with a plurality of metal strips perpendicular to the metal ring, and a length of the metal strip is less than a distance between two adjacent metal rings. 
     
     
         11 . The stacked spiral inductor of  claim 10 , wherein a fixed distance is maintained between the metal strips, and an end of each metal strip is connected to the metal ring to be grounded through the metal ring. 
     
     
         12 . The stacked spiral inductor of  claim 10 , wherein a number of the metal rings is equal to a number of the inductive metal layers. 
     
     
         13 . The stacked spiral inductor of  claim 10 , wherein the metal ring and the conductive coil are similar in shape. 
     
     
         14 . The stacked spiral inductor of  claim 12 , wherein the metal strips corresponding to the metal rings from an outermost metal ring to an innermost metal ring are sequentially correspondingly perpendicular to the conductive coils of the inductive metal layers from a top inductive metal layer to a bottom inductive metal layer respectively, wherein the metal strips of the outermost metal ring are perpendicular to the conductive coil of the top inductive metal layer correspondingly, and the metal strips of the innermost metal ring are perpendicular to the conductive coil of the bottom inductive metal layer correspondingly. 
     
     
         15 . The stacked spiral inductor of  claim 1 , wherein the insulating layer is an oxide layer. 
     
     
         16 . The stacked spiral inductor of  claim 1 , wherein the conductive coils of the inductive metal layers are similar in shape. 
     
     
         17 . The stacked spiral inductor of  claim 1 , wherein the conductive coil located on the same inductive metal layer has the same line width. 
     
     
         18 . The stacked spiral inductor of  claim 1 , wherein the conductive coils on the inductive metal layers from a top inductive metal layer to a bottom inductive metal layer have the same line width. 
     
     
         19 . The stacked spiral inductor of  claim 1 , wherein the conductive coils on the inductive metal layers from a top inductive metal layer to a bottom inductive metal layer have line widths changing in a gradually increasing trend or in a gradually decreasing trend. 
     
     
         20 . The stacked spiral inductor of  claim 5 , wherein a line width of the first extending portion is equal to a line width of the second extending portion, and the line width of the first extending portion and the line width of the second extending portion are ⅓ of a line width of the conductive coil.