Metallization system for semiconductor devices, devices utilizing such metallization system and method for making devices and metallization system

• US 3,987,217 A
• Filed: 10/16/1974
• Issued: 10/19/1976
• Est. Priority Date: 01/03/1974
• Status: Expired due to Term

• Current Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Greeson, Richard L., Philofsky, Elliott M.
• Primary Examiner(s): Esposito, Michael F.
• Application Number:
  US05/515,278
• Time in Patent Office: 734 Days
• Field of Search: 357/67, 357/71, 117/217, 117/107, 204/38 B, 204/41 R, 204/67, 204/71, 427/89, 427/90, 427/91, 427/123, 427/124, 427/250, 427/314, 427/319, 427/320
• US Class Current: 438/652
• CPC Class Codes: B23K 2035/008 at least one of the workpieces being of silicium
• CPC Class Codes: B23K 35/001 Interlayers, transition pieces for metallurgical bonding of workpieces
• CPC Class Codes: C23C 14/16 on metallic substrates or on substrates of boron or silicon
• CPC Class Codes: H01L 2224/29111 Tin [Sn] as principal constituent
• CPC Class Codes: H01L 2224/8319 Arrangement of the layer connectors prior to mounting
• CPC Class Codes: H01L 2224/83801 Soldering or alloying
• CPC Class Codes: H01L 23/051 another lead being formed by a cover plate parallel to the base plate, e.g. sandwich type
• CPC Class Codes: H01L 23/485 consisting of layered constructions comprising conductive layers and insulating layers, e.g. planar contacts H01L23/4821, H01L23/4822, H01L23/4824, H01L23/4825 take precedence; materials H01L23/532, bond pads H01L24/02, bump connectors H01L24/10
• CPC Class Codes: H01L 23/4924 characterised by the materials
• CPC Class Codes: H01L 24/01 Means for bonding being attached to, or being formed on, the surface to be connected, e.g. chip-to-package, die-attach, "first-level" interconnects; Manufacturing methods related thereto
• CPC Class Codes: H01L 24/33 of a plurality of layer connectors
• CPC Class Codes: H01L 24/83 using a layer connector
• 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 2924/01005 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 2924/01019 Potassium [K]
• CPC Class Codes: H01L 2924/01027 Cobalt [Co]
• CPC Class Codes: H01L 2924/01029 : Copper [Cu]
• CPC Class Codes: H01L 2924/01032 : Germanium [Ge]
• CPC Class Codes: H01L 2924/01033 : Arsenic [As]
• CPC Class Codes: H01L 2924/01042 : Molybdenum [Mo]
• CPC Class Codes: H01L 2924/01045 : Rhodium [Rh]
• 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 2924/01074 : 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 2924/0132 : Binary Alloys
• CPC Class Codes: H01L 2924/01322 : Eutectic Alloys, i.e. obtained by a liquid transforming into two solid phases
• CPC Class Codes: H01L 2924/01327 : Intermediate phases, i.e. intermetallics compounds
• CPC Class Codes: H01L 2924/0133 : Ternary Alloys
• CPC Class Codes: H01L 2924/014 : Solder alloys
• CPC Class Codes: H01L 2924/10253 : Silicon [Si]
• CPC Class Codes: H01L 2924/12035 : Zener diode
• CPC Class Codes: H01L 2924/12042 : LASER
• CPC Class Codes: H01L 2924/3512 : Cracking

Abstract

A metallization system for metallurgically bonding a semiconductor die to metallic conducting slugs as terminals at the same time, and at the same temperature, that a surrounding glass sleeve is hermetically sealed to the conducting slugs for forming a zener diode, for example, is disclosed. The metallization system comprises a combination of aluminum, tin and palladium, for bonding to molybdenum, the aluminum being vapor deposited followed by a vapor co-deposition of aluminum and tin and further followed by a vapor deposited layer of palladium.

A method of making a device is disclosed wherein the die, two metal slugs of molybdenum and a preformed high temperature sealing glass are assembled together and subjected to a time-temperature cycle which includes a rapid rise to a high temperature at which metallurgical bonding of the die to the metal slugs and hermetic sealing of the glass to the metal slugs take place in a short time interval followed by rapid cooling of the assembly to a temperature slightly below the eutectic of aluminum and silicon.

Claims

1. The method of forming a metallization system on a semiconductor surface for subsequent bonding to an electrode comprising the steps of:

a. providing a semiconductor die having a surface;

b. depositing a first layer of aluminum having a thickness of about 2,500 A on said surface; and

c. depositing a second layer comprising a mixture of aluminum and tin on said first layer of aluminum wherein the aluminum comprises an equivalent thickness of about 2,500 A and the tin comprises an equivalent thickness of about 20,000 A; and

the metallization system includes a third layer of palladium of about 800 A to 1,000 A thickness.

2. The method of forming a metallization system on a semiconductor surface for subsequent bonding to an electrode comprising the steps of:

a. preheating said semiconductor surface to about 200°

C;

b. forming an aluminum-silicon alloy on such surface and a layer of aluminum thereover wherein said forming of an aluminum-silicon alloy and of a layer of aluminum comprises deposition by evaporation of about 2,500 A thickness of aluminum;

c. removing said preheat; and

d. forming a mixture of aluminum and tin on said layer of aluminum wherein said forming of said mixture of aluminum and tin comprises evaporation of an alloy of about 90-10 tin-aluminum, respectively to about an equivalent thickness of 2,500 A of aluminum and an equivalent thickness of about 20,000 A of tin; and

the metallization system includes the evaporation of a layer of palladium of about 800 A to 1,000 A thickness on said mixture of aluminum and tin.

3. The method of forming a metallization system on a semiconductor surface for subsequent bonding to an electrode comprising the steps of:

a. preheating said semiconductor surface to about 200°

C;

b. forming an aluminum-silicon alloy on said surface and a layer of aluminum thereover wherein said forming of an aluminum-silicon alloy and a layer of aluminum comprises deposition by evaporation of about 2,500 A thickness of aluminum;

c. removing said preheat; and

d. forming a mixture of aluminum and tin on said layer of aluminum wherein said forming of a mixture of aluminum and tin comprises evaporation of about equal volumes but separate components of aluminum and tin to give in said mixture an equivalent thickness of about 2,500 A of aluminum and an equivalent thickness of about 20,000 A of tin; and

the metallization system includes the evaporation of a layer of palladium of about 800 A to about 1,000 A thickness on said mixture of aluminum and tin.