Abstract:
An integrated circuit device includes a semiconductor device having an integrated circuit. A gas-phase deposited insulation layer is disposed on the semiconductor device, and a conducting line is disposed over the gas-phase deposited insulation layer.

Description:
BACKGROUND 
     Semiconductor devices, such as integrated circuit (IC) packages, typically include one or more semiconductor devices arranged on a lead frame or carrier. The semiconductor device is attached to the lead frame, typically by an adhesive die attach material or by soldering, and bond wires are attached to bond pads on the semiconductor devices and to lead fingers on the carrier to provide electrical interconnections between the various semiconductor devices and/or between a semiconductor device and the carrier. The device is then encapsulated in a plastic housing, for instance, to provide protection and form a housing from which the leads extend. 
     With such semiconductor packages, especially power semiconductor components, it is desirable to provide high current load-carrying capacity. To this end, some solutions for providing the desired connection density or current capacity require an insulation layer to avoid electrical contact between the conductive connections and the semiconductor device/carrier. 
     For these and other reasons, there is a need for the present invention. 
     SUMMARY 
     In accordance with aspects of the present disclosure, an integrated circuit device includes a semiconductor device having an integrated circuit. A gas-phase deposited insulation layer is disposed on the semiconductor device, and a conducting line is disposed over the gas-phase deposited insulation layer. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Embodiments of the invention are better understood with reference to the following drawings. The elements of the drawings are not necessarily to scale relative to each other. Like reference numerals designate corresponding similar parts. 
         FIG. 1  is a block diagram conceptually illustrating a top view of an integrated circuit device in accordance with embodiments of the present invention. 
         FIGS. 2-6  are side views conceptually illustrating various aspects of an integrated circuit device in accordance with embodiments of the present invention. 
         FIG. 7  is a block diagram conceptually illustrating a top view of a multi-chip module in accordance with embodiments of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     In the following Detailed Description, reference is made to the accompanying drawings, which form a part hereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. In this regard, directional terminology, such as “top,” “bottom,” “front,” “back,” “leading,” “trailing,” etc., is used with reference to the orientation of the Figure(s) being described. Because components of embodiments of the present invention can be positioned in a number of different orientations, the directional terminology is used for purposes of illustration and is in no way limiting. It is to be understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope of the present invention. The following detailed description, therefore, is not to be taken in a limiting sense, and the scope of the present invention is defined by the appended claims. 
       FIG. 1  is a schematic top view conceptually illustrating an integrated circuit device in accordance with exemplary embodiments of the present invention. The exemplary integrated circuit device  100  includes a semiconductor device, or chip,  110  attached to a lead frame or carrier  112 . An insulation layer  114  is deposited over the chip  110 , and a conductive layer including conductive lines  116  is deposited over the insulation layer  114  to provide electrical interconnections between the chip  110  and the carrier  112 . For example, in certain embodiments, the conductive layer  116  includes generally flat copper strips interconnecting the chip  110  with source and gate terminals  120 ,  122 . 
     As illustrated in  FIG. 1 , the planar conductive connections  116  to the source terminals  120  are relatively wide (100 μm or more in exemplary embodiments) to provide the desired current and heat conductivity. The connection to the gate terminal  122  in the illustrated embodiment is thinner, allowing smaller lateral structures. 
     In accordance with aspects of the invention, the insulation layer  114  is gas-phase deposited. Among other things, using a gas-phase deposition rather than foil technology provides improved adhesion of the insulation layer  114  on the chip  110  and carrier  112 . Further, applying the insulation layer from the gas phase can provide better surface wetting, a higher surface reactivity and good conformance to the surface topography under the insulation layer  114 . Still further, the gas-phase deposited insulation layer  114  has a high thermal stability and imparts a relatively small thermal-mechanical stress on the device since the process can take place at ambient temperature in certain implementations. 
       FIGS. 2-6  conceptually illustrate side views of portions of the integrated circuit device  100  in a block diagram form. In  FIG. 2 , the semiconductor device  110  is attached to the lead frame  112 , which includes a source potion  120  and drain portion  122  separated by a gap  124 . In exemplary embodiments, the semiconductor device  110  is attached in a conventional manner, such as with an adhesive die attach material or tape, soldering, etc. In  FIG. 3 , the gap  124  between the source  120  and drain  122  is filled with an insulating material  126  to prevent shorts between the source  120  and drain  122 . The insulating material  126  permanently or temporarily fills the gap  124  to facilitate the process of applying an insulation layer. 
       FIG. 4  illustrates the insulation layer  114  deposited over the chip  110  and lead frame  112 . Typically, materials such as epoxy, polyamide or silicone would be used for the insulation layer  114 , and would be applied in the liquid phase, for example, by a spin coating process. In the illustrated embodiment the insulation layer  114  is deposited in the gas phase, for example, by a chemical vapor deposition (CVD). In exemplary embodiments, the insulation layer  114  thickness varies from about 1-100 μm, 20-50 μm thick in certain embodiments. 
     In one embodiment, the insulation layer  114  is a plasmapolymer, and in particular, the plasmapolymer is a Parylene, such as Parylene C, Parylene N, or Parylene D. Parylenes are particularly well suited as insulation materials. They have a high electrical insulation strength. In addition, Parylene takes up only very little moisture and is comparatively elastic, so that it can buffer thermomechanical stresses between the semiconductor device  110  and adjacent layers. In addition, Parylenes often have low coefficients of thermal expansion of less than 50 ppm/K, a high thermal stability and a high chemical resistance. 
     Particularly, Parylene C provides a useful combination of chemical and physical properties plus a very low permeability to moisture, chemicals and other corrosive gases. Parylene C has a melting point of 290° C. Parylene N provides high dielectric strength and a dielectric constant that does not vary with changes in frequency. Parylene N has a melting point of 420° C. Parylene D maintains its physical strength and electrical properties at higher temperatures. Parylene D has a melting point of 380° C. 
     In another embodiment, the insulation layer  114  includes an amorphous inorganic or ceramic carbon type layer. The amorphous inorganic or ceramic carbon type layer has an extremely high dielectrical breakthrough strength and a coefficient of thermal expansion (CTE) of about 2-3 ppm/K, which is very close to the CTE of silicon of about 2.5 ppm/K. In addition, the amorphous inorganic or ceramic carbon type layer has a temperature stability up to 450-500° C. 
       FIG. 5  illustrates the device  100  with the insulation layer  114  formed, such as by photolithographic processes, etching, laser ablation, etc. In  FIG. 6 , the device  100  is illustrated including the conductive layer  116  deposited on the insulation layer  114 , providing interconnections between the chip  110  and the periphery of lead frame  112 . The device can then be encapsulated, by any suitable molding process, for example, resulting in the encapsulation or housing  130 . 
     The process disclosed above is also suitable also for the contacting of a plurality of semiconductor devices in a multi-chip module. In such a multi-chip module, the interconnections between the semiconductor components can be produced in the same way and at the same time as the connections from the semiconductor devices to the periphery of the carrier.  FIG. 7  illustrates an exemplary multi-chip module  200  in accordance with embodiments of the invention. The multi-chip module  200  includes semiconductor devices situated on a carrier  112 . A gas-phase deposited insulation layer  114  is deposited over the semiconductor devices and the carrier  112 , and the multi-chip module  200  is surrounded by an encapsulation  130 . 
     The semiconductor devices include first and second power transistors  210 , 212  mounted on the carrier  112 . A logic device  214  is mounted on the power transistor  210 . Alternatively, the logic device  214  can be arranged along side the power transistors  210 , 212  if space allows. The power transistors  210 , 212  are arranged in a half bridge configuration, with the drain connection  220  of the high side device  212  connected to the source  222  of the low side device  210  by conductive lines  116  deposited on the insulation layer  114 . The logic device  214  is connected for controlling the power transistors  210 , 212  via their gate contacts  224 . Conductive connections  116  are further situated between various terminals of the semiconductor devices and contacts  230  situated at the periphery of the package  200 , with the insulation layer  114  situated between the chips/carrier and the deposited conductive connections  116 . The configuration shown can be extended the addition of further semiconductor components as well as passive elements, for example. 
     Although specific embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that a variety of alternate and/or equivalent implementations may be substituted for the specific embodiments shown and described without departing from the scope of the present invention. This application is intended to cover any adaptations or variations of the specific embodiments discussed herein. Therefore, it is intended that this invention be limited only by the claims and the equivalents thereof.