Semiconductor device and a manufacturing method of the same

• US 8,138,598 B2
• Filed: 01/13/2010
• Issued: 03/20/2012
• Est. Priority Date: 07/30/2004
• Status: Active Grant

• Current Assignee: Renesas Electronics Corporation
• Original Assignee: Renesas Electronics Corporation
• Inventors: Shiraishi, Masaki, Uno, Tomoaki, Matsuura, Nobuyoshi
• Primary Examiner(s): Louie, Wai-Sing
• Assistant Examiner(s): Jahan, Bilkis
• Application Number:
  US12/686,595
• Publication Number:
  US 20100117225A1
• Time in Patent Office: 797 Days
• Field of Search: 257/723, 257/777, 257/666, 257/676, 257/778, 257/724, 257/686
• US Class Current: 257/723
• CPC Class Codes: H01L 21/28035 the final conductor layer next to the insulator being silicon, e.g. polysilicon, with or without impurities H01L21/28105 takes precedence
• CPC Class Codes: H01L 21/823475 interconnection or wiring or contact manufacturing related aspects
• CPC Class Codes: H01L 2224/0401 Bonding areas specifically adapted for bump connectors, e.g. under bump metallisation [UBM]
• CPC Class Codes: H01L 2224/04042 Bonding areas specifically adapted for wire connectors, e.g. wirebond pads
• CPC Class Codes: H01L 2224/05554 being square
• CPC Class Codes: H01L 2224/05624 Aluminium [Al] as principal constituent
• CPC Class Codes: H01L 2224/0603 Bonding areas having different sizes, e.g. different heights or widths
• CPC Class Codes: H01L 2224/32245 the item being metallic
• CPC Class Codes: H01L 2224/371 with a principal constituent of the material being a metal or a metalloid, e.g. boron [B], silicon [Si], germanium [Ge], arsenic [As], antimony [Sb], tellurium [Te] and polonium [Po], and alloys thereof
• CPC Class Codes: H01L 2224/37124 Aluminium [Al] as principal constituent
• CPC Class Codes: H01L 2224/37147 Copper [Cu] as principal constituent
• CPC Class Codes: H01L 2224/40095 Kinked
• CPC Class Codes: H01L 2224/40245 the item being metallic
• CPC Class Codes: H01L 2224/40247 Connecting the strap to a bond pad of the item
• CPC Class Codes: H01L 2224/45015 being circular
• CPC Class Codes: H01L 2224/45144 Gold (Au) as principal constituent
• CPC Class Codes: H01L 2224/48011 Length
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48095 Kinked
• CPC Class Codes: H01L 2224/48137 the bodies being arranged next to each other, e.g. on a common substrate
• CPC Class Codes: H01L 2224/48247 : connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/48253 : connecting the wire to a potential ring of the item
• CPC Class Codes: H01L 2224/48624 : Aluminium (Al) as principal constituent
• CPC Class Codes: H01L 2224/4903 : Connectors having different sizes, e.g. different diameters
• CPC Class Codes: H01L 2224/49051 : Connectors having different shapes
• CPC Class Codes: H01L 2224/49111 : the connectors connecting two common bonding areas, e.g. Litz or braid wires
• CPC Class Codes: H01L 2224/49171 : Fan-out arrangements
• CPC Class Codes: H01L 2224/49175 : Parallel arrangements
• CPC Class Codes: H01L 2224/73221 : Strap and wire connectors
• CPC Class Codes: H01L 2224/73265 : Layer and wire connectors
• CPC Class Codes: H01L 2224/8385 : using a polymer adhesive, e.g. an adhesive based on silicone, epoxy, polyimide, polyester
• CPC Class Codes: H01L 2224/84801 : Soldering or alloying
• CPC Class Codes: H01L 2224/8485 : using a polymer adhesive, e.g. an adhesive based on silicone, epoxy, polyimide, polyester
• CPC Class Codes: H01L 23/3107 : the device being completely enclosed
• CPC Class Codes: H01L 23/49524 : the additional leads being a tape carrier or flat leads
• CPC Class Codes: H01L 23/49562 : for devices being provided for in H01L29/00
• CPC Class Codes: H01L 23/49575 : Assemblies of semiconductor devices on lead frames
• CPC Class Codes: H01L 24/06 : of a plurality of bonding areas
• CPC Class Codes: H01L 24/37 : of an individual strap connector
• CPC Class Codes: H01L 24/40 : of an individual strap connector
• CPC Class Codes: H01L 24/45 : of an individual wire connector
• CPC Class Codes: H01L 24/48 : of an individual wire connector
• CPC Class Codes: H01L 24/49 : of a plurality of wire connectors
• CPC Class Codes: H01L 24/73 : Means for bonding being of different types provided for in two or more of groups H01L24/10, H01L24/18, H01L24/26, H01L24/34, H01L24/42, H01L24/50, H01L24/63, H01L24/71
• CPC Class Codes: H01L 24/84 : using a strap connector
• CPC Class Codes: H01L 27/0629 : in combination with diodes, or resistors, or capacitors
• CPC Class Codes: H01L 29/1095 : Body region, i.e. base region, of DMOS transistors or IGBTs cell layout H01L29/0696
• CPC Class Codes: H01L 29/41741 : for vertical or pseudo-vertical devices
• CPC Class Codes: H01L 29/4232 : with insulated gate
• CPC Class Codes: H01L 29/4236 : within a trench, e.g. trench gate electrode, groove gate electrode
• CPC Class Codes: H01L 29/4238 : characterised by the surface lay-out
• CPC Class Codes: H01L 29/45 : Ohmic electrodes
• CPC Class Codes: H01L 29/456 : on silicon
• CPC Class Codes: H01L 29/4916 : the conductor material next to the insulator being a silicon layer, e.g. polysilicon doped with boron, phosphorus or nitrogen H01L29/4908, H01L29/4983 take precedence
• CPC Class Codes: H01L 29/66143 : Schottky diodes
• CPC Class Codes: H01L 29/66734 : with a step of recessing the gate electrode, e.g. to form a trench gate electrode
• CPC Class Codes: H01L 29/7806 : the other device being a Schottky barrier diode
• CPC Class Codes: H01L 29/7813 : with trench gate electrode, e.g. UMOS transistors trench gate electrodes per se H01L29/4236
• CPC Class Codes: H01L 29/872 : Schottky diodes
• CPC Class Codes: H01L 2924/00 : Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/00012 : Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• CPC Class Codes: H01L 2924/00014 : the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/01002 : Helium [He]
• CPC Class Codes: H01L 2924/01004 : Beryllium [Be]
• CPC Class Codes: H01L 2924/01005 : Boron [B]
• CPC Class Codes: H01L 2924/01006 : Carbon [C]
• CPC Class Codes: H01L 2924/01013 : Aluminum [Al]
• CPC Class Codes: H01L 2924/01014 : Silicon [Si]
• CPC Class Codes: H01L 2924/01015 : Phosphorus [P]
• CPC Class Codes: H01L 2924/01021 : Scandium [Sc]
• CPC Class Codes: H01L 2924/01022 : Titanium [Ti]
• CPC Class Codes: H01L 2924/01023 : Vanadium [V]
• CPC Class Codes: H01L 2924/01027 : Cobalt [Co]
• CPC Class Codes: H01L 2924/01028 : Nickel [Ni]
• CPC Class Codes: H01L 2924/01029 : Copper [Cu]
• CPC Class Codes: H01L 2924/01033 : Arsenic [As]
• CPC Class Codes: H01L 2924/01046 : Palladium [Pd]
• CPC Class Codes: H01L 2924/01047 : Silver [Ag]
• CPC Class Codes: H01L 2924/0105 : Tin [Sn]
• CPC Class Codes: H01L 2924/01057 : Lanthanum [La]
• CPC Class Codes: H01L 2924/01072 : Hafnium [Hf]
• CPC Class Codes: H01L 2924/01074 : Tungsten [W]
• CPC Class Codes: H01L 2924/01078 : Platinum [Pt]
• CPC Class Codes: H01L 2924/01079 : Gold [Au]
• CPC Class Codes: H01L 2924/01082 : Lead [Pb]
• CPC Class Codes: H01L 2924/014 : Solder alloys
• CPC Class Codes: H01L 2924/12032 : Schottky diode
• CPC Class Codes: H01L 2924/1305 : Bipolar Junction Transistor [BJT]
• CPC Class Codes: H01L 2924/1306 : Field-effect transistor [FET]
• CPC Class Codes: H01L 2924/13091 : Metal-Oxide-Semiconductor Field-Effect Transistor [MOSFET]
• CPC Class Codes: H01L 2924/14 : Integrated circuits
• CPC Class Codes: H01L 2924/1532 : the connection portion being formed on the die mounting surface of the substrate
• CPC Class Codes: H01L 2924/181 : Encapsulation
• CPC Class Codes: H01L 2924/19041 : being a capacitor
• CPC Class Codes: H01L 2924/19043 : being a resistor
• CPC Class Codes: H01L 2924/20753 : larger or equal to 30 microns less than 40 microns
• CPC Class Codes: H01L 2924/20755 : larger or equal to 50 microns less than 60 microns
• CPC Class Codes: H01L 2924/30105 : Capacitance
• CPC Class Codes: H01L 2924/30107 : Inductance
• CPC Class Codes: H01L 2924/3011 : Impedance
• CPC Class Codes: H02M 3/003 : Constructional details, e.g. physical layout, assembly, wiring or busbar connections
• CPC Class Codes: H02M 3/155 : using semiconductor devices only
• CPC Class Codes: H02M 7/003 : Constructional details, e.g. physical layout, assembly, wiring or busbar connections

Abstract

In a non-insulated DC-DC converter having a circuit in which a power MOS•FET high-side switch and a power MOS•FET low-side switch are connected in series, the power MOS•FET low-side switch and a Schottky barrier diode to be connected in parallel with the power MOS•FET low-side switch are formed within one semiconductor chip. The formation region SDR of the Schottky barrier diode is disposed in the center in the shorter direction of the semiconductor chip, and on both sides thereof, the formation regions of the power MOS•FET low-side switch are disposed. From the gate finger in the vicinity of both long sides on the main surface of the semiconductor chip toward the formation region SDR of the Schottky barrier diode, a plurality of gate fingers are disposed so as to interpose the formation region SDR between them.

Claims

1. A semiconductor device including a DC-DC converter, comprising:

a first die pad having an input power supply terminal;

a second die pad having an output terminal;

a third die pad;

a lead having a reference potential terminal, which is adjacent to the second die pad;

a first semiconductor chip including a high side MOSFET of the DC-DC converter, which is mounted over the first die pad,

the first semiconductor chip having a first gate electrode pad, a first source electrode pad and a first drain electrode of the high side MOSFET,

the first drain electrode being electrically coupled to the input power supply terminal,

the first source electrode pad being electrically coupled to the output terminal;

a second semiconductor chip including a low side MOSFET of the DC-DC converter, which is mounted over the second die pad,

the second semiconductor chip having a second gate electrode pad, a second source electrode pad and a second drain electrode of the low side MOSFET,

the second source electrode pad being electrically coupled to the reference potential terminal,

the second drain electrode being electrically coupled to the output terminal;

a third semiconductor chip including a first driver circuit driving the high side MOSFET and a second driver circuit driving the low side MOSFET, which is mounted over the third die pad,

the third semiconductor chip having a first electrode pad electrically coupled to an output of the first driver circuit and a second electrode pad electrically coupled to an output of the second driver circuit,

a first bonding wire for electrically coupling the first electrode pad of the third semiconductor chip and the first gate electrode pad of the first semiconductor chip;

a second bonding wire for electrically coupling the second electrode pad of the third semiconductor chip and the second gate electrode pad of the second semiconductor chip;

a first metal sheet interconnect coupled to the first source electrode pad of the first semiconductor chip and the second die pad,

the first source electrode pad of the first semiconductor chip and the second drain electrode of the second semiconductor chip being electrically coupled via the first metal sheet interconnect and the second die pad;

a second metal sheet interconnect coupled to the second source electrode pad of the second semiconductor chip and the lead; and

a resin body covering the first, second and third semiconductor chips,

the input power supply terminal being exposed from the resin body,

the reference potential terminal being exposed from the resin body,

the output terminal being exposed from the resin body,

wherein a Schottky Barrier Diode is formed in the second semiconductor chip, and

an anode and a cathode of the Schottky Barrier Diode are electrically coupled to the second source electrode pad and the second drain electrode of the second semiconductor chip, respectively.

2. A semiconductor device according to claim 1, wherein the second semiconductor chip comprising:

a semiconductor substrate of n-type having a first major surface and a second major surface opposite to the first major surface,

the drain electrode formed over the second major surface and electrically connected to the semiconductor substrate;

an epitaxial layer of n-type formed over the first major surface of the semiconductor substrate and electrically connected to the semiconductor substrate; and

the second source electrode pad formed on the epitaxial layer,

wherein the source electrode pad and the epitaxial layer form a Schottky contact of the Schottky barrier diode.

3. A semiconductor device according to claim 2, wherein the epitaxial layer is made of silicon;

and

the second electrode pad is made of aluminum.

4. A semiconductor device according to claim 2, wherein the second semiconductor chip includes:

a Schottky barrier diode formation region in which the Schottky barrier diode is formed and a transistor cell formation regions in which the low side MOSFET is formed;

an n-type well formed in the epitaxial layer in the transistor cell formation region, an impurity concentration of the n-type well being greater than that of the epitaxial layer;

a channel formation region of the low side MOSFET formed over the n-type well in the transistor cell formation region, the channel formation region having p-type;

a source region of the low side MOSFET formed over the channel formation region in the transistor cell formation region, the source region having n-type; and

a gate electrode of the low side MOSFET formed over the n-type well in the transistor cell formation region,

wherein the n-type well is not formed in the Schottky barrier diode formation region.

5. A semiconductor device according to claim 1, wherein the second semiconductor chip has a Schottky barrier diode formation region in which the Schottky barrier diode is formed and a transistor cell formation regions in which the low side MOSFET is formed;

the Schottky barrier diode formation region is located between the transistor cell formation regions.

6. A semiconductor device according to claim 1, wherein the first and second metal sheet interconnects are made of copper.

7. A semiconductor device according to claim 1, wherein widths of the first and second metal sheet interconnects are greater than that of the first and second bonding wires.

8. A semiconductor device according to claim 1, wherein the first semiconductor chip has a rectangular shape having a pair of long sides and a pair of short sides in a plan view;

and

the first metal sheet interconnect is disposed so as to overlap with one of the long sides in plan view.

9. A semiconductor device according to claim 8, wherein the one of the long sides of the first semiconductor chip faces toward the second semiconductor chip.

10. A semiconductor device according to claim 8, wherein the first semiconductor chip has a pair of the first source electrode pads;

and

the first metal sheet interconnect is electrically and mechanically connected to the pair of the first source electrode pads.