Semiconductor device and a method of manufacturing the same

Abstract

Provided is a semiconductor device comprising a first metal film formed above a semiconductor chip, a ball portion formed over said first metal film and made of a second metal, and an alloy layer of said first metal and said second metal which alloy layer is formed between said first metal film and said ball portion, wherein said alloy layer reaches the bottom of said first metal film, and said ball portion is covered with a resin; and a manufacturing method thereof. The present invention makes it possible to improve adhesion between the bonding pad portion and ball portion of a bonding wire over an interconnect, thereby improving the reliability of the semiconductor device.

What is claimed is:  
     
         1 . A semiconductor device comprising: 
 (a) a first metal film formed above a semiconductor chip;    (b) a ball portion formed over said first metal film and made of a second metal; and    (c) an alloy layer of said first metal and said second metal which alloy layer has been formed between said first metal film and said ball portion,    (d) wherein said alloy layer reaches the bottom of said first metal film, and    (e) wherein said ball portion has been covered with a resin.    
     
     
         2 . A semiconductor device comprising: 
 (a) an Al film formed above a semiconductor chip and having aluminum (Al) as a main component;    (b) a ball portion formed over said Al film and having gold (Au) as a main component; and    (c) an aluminum-gold alloy layer formed between said first Al film and said gold ball portion,    (d) wherein said alloy layer reaches the bottom of said Al film, and    (e) wherein said gold ball portion has been covered with a resin.    
     
     
         3 . A semiconductor device according to  claim 2 , wherein said alloy layer contains an AlAu 4  film.  
     
     
         4 . A semiconductor device according to  claim 2 , wherein said alloy layer is comprised of a laminate film and a gold composition ratio of said laminate film relative to aluminum increases from a lower layer toward an upper layer.  
     
     
         5 . A semiconductor device according to  claim 2 , wherein said alloy layer has an AlAu 2  film, an Al 2 Au 5  film and an AlAu 4  film in the order from the lower layer.  
     
     
         6 . A semiconductor device according to  claim 2 , wherein said Al film has a thickness of 700 nm or less.  
     
     
         7 . A semiconductor device according to  claim 2 , 
 wherein said semiconductor device has a plurality of said Al films,    wherein said plurality of Al films have been covered with an insulating film having an opening at each of pad regions, and    wherein the shortest distance between any adjacent two of said pad regions is 70 μm or less.    
     
     
         8 . A semiconductor device according to  claim 2 , wherein said gold portion has a maximum peripheral diameter of 65 μm or less.  
     
     
         9 . A semiconductor device according to  claim 2 , wherein the relationship between the height h of said gold ball portion and the maximum peripheral diameter D of said gold ball portion satisfies the following expression: 9≧D/h≧2.  
     
     
         10 . A semiconductor device according to  claim 2 , wherein the height of said gold ball portion is 15 μm or less.  
     
     
         11 . A semiconductor device according to  claim 2 , wherein the height of said gold ball portion is 5 μm or greater but not greater than 15 μm.  
     
     
         12 . A semiconductor device according to  claim 2 , wherein a gold wire extends to an external connecting terminal from an upper portion of said gold ball portion.  
     
     
         13 . A semiconductor device comprising: 
 (a) a first metal film formed above a semiconductor chip;    (b) a ball portion formed over said first metal film and made of a second metal; and    (c) an alloy layer of said first metal and said second metal which alloy layer has been formed between said first metal film and said ball portion,    (d) wherein said alloy layer reaches the bottom of said first metal film, and    (e) wherein the relationship between the height h of said gold ball portion and the maximum peripheral diameter D of said gold ball portion satisfies the following expression: 9≧D/h≧2.    
     
     
         14 . A semiconductor device according to  claim 13 , wherein said first metal film has aluminum (Al) as a main component and said ball portion has gold (Au) as a main component.  
     
     
         15 . A semiconductor device according to  claim 14 , wherein said alloy layer contains an AlAu 4  film.  
     
     
         16 . A semiconductor device according to  claim 14 , wherein said alloy layer is comprised of a laminate film and a gold composition ratio of said laminate film relative to aluminum increases from the lower layer toward the upper layer.  
     
     
         17 . A semiconductor device according to  claim 14 , wherein said alloy layer has an AlAu 2  film, an Al 2 Au 5  film and an AlAu 4  film in the order from the lower layer.  
     
     
         18 . A semiconductor device according to  claim 14 , wherein said Al film has a thickness of 700 nm or less.  
     
     
         19 . A semiconductor device according to  claim 14 , 
 wherein said semiconductor device has a plurality of said Al films,    wherein said plurality of Al films have been covered with an insulating film having an opening at each of pad regions, and    wherein the shortest distance between any adjacent two of said pad regions is 70 μm or less.    
     
     
         20 . A semiconductor device according to  claim 14 , wherein said gold ball portion has a maximum peripheral diameter of 65 μm or less.  
     
     
         21 . A semiconductor device according to  claim 14 , wherein said gold ball portion has a height of 15 μm or less.  
     
     
         22 . A semiconductor device according to  claim 14 , wherein said gold ball portion has a height of 5 μm or greater but not greater than 15 μm or less.  
     
     
         23 . A semiconductor device according to  claim 14 , wherein from an upper portion of said gold ball portion, a gold wire extends to an external connecting terminal.  
     
     
         24 . A semiconductor device comprising: 
 (a) a first metal film formed above a semiconductor chip;    (b) a ball portion formed over said first metal film and made of a second metal; and    (c) an alloy layer of said first metal and said second metal which alloy layer is formed between said first metal film and said ball portion,    (d) wherein the relationship between a diameter d of a contact region of said first metal film with said ball portion and a diameter g of said alloy layer formed region satisfies the following expression: g≧0.8d.    
     
     
         25 . A semiconductor device according to  claim 24 , wherein said first metal film has aluminum (Al) as a main component and said ball portion has gold (Au) as a main component.  
     
     
         26 . A semiconductor device according to  claim 24 , wherein said alloy layer reaches the bottom of said first metal film.  
     
     
         27 . A semiconductor device according to  claim 24 , wherein the relationship between a diameter d of said contact region and the maximum peripheral diameter D of said ball portion satisfies the following expression: d≧0.8D.  
     
     
         28 . A semiconductor device according to  claim 24 , wherein said contact region is at least 70% of a region defined by the maximum periphery of said ball portion.  
     
     
         29 . A semiconductor device according to  claim 25 , wherein said alloy layer contains an AlAu 4  film.  
     
     
         30 . A semiconductor device according to  claim 25 , wherein said alloy layer is comprised of a laminate film and a gold composition ratio of said laminate film relative to aluminum increases from a lower layer toward an upper layer.  
     
     
         31 . A semiconductor device according to  claim 25 , wherein said alloy layer has an AlAu 2  film, an Al 2 Au 5  film and an AlAu 4  film in the order from the lower layer.  
     
     
         32 . A semiconductor device according to  claim 25 , wherein said Al film has a thickness of 700 nm or less.  
     
     
         33 . A semiconductor device according to  claim 25 , 
 wherein said semiconductor device has a plurality of said Al films,    wherein said plurality of Al films have been covered with an insulating film having an opening at each of pad regions, and    wherein the shortest distance between any adjacent two of said pad regions is 70 μm or less.    
     
     
         34 . A semiconductor device according to  claim 25 , wherein said ball portion having gold (Au) as a main component has a maximum peripheral diameter of 65 μm or less.  
     
     
         35 . A semiconductor device according to  claim 25 , wherein the relationship between the height h of said ball portion having gold (Au) as a main component and the maximum peripheral diameter D of said gold ball portion satisfies the following expression: 9≧D/h≧2.  
     
     
         36 . A semiconductor device according to  claim 25 , wherein said ball portion having gold (Au) as a main component has a height of 15 μm or less.  
     
     
         37 . A semiconductor device according to  claim 25 , wherein said ball portion having gold (Au) as a main component has a height of 5 μm or greater but not greater than 15 μm.  
     
     
         38 . A semiconductor device according to  claim 25 , wherein from an upper portion of said ball portion having gold (Au) as a main component, a gold wire extends to an external connecting terminal.  
     
     
         39 . A semiconductor device comprising: 
 (a) a first metal film formed above a semiconductor chip;    (b) a ball portion formed over said first metal film and made of a second metal; and    (c) an alloy layer of said first metal and said second metal which alloy layer has been formed between said first metal film and said ball portion,    (d) wherein an alloy layer has been formed in at least 70% of a contact region of said first metal film with said ball portion.    
     
     
         40 . A semiconductor device according to  claim 39 , wherein the relationship between a diameter d of said contact region and a maximum peripheral diameter D of said ball portion satisfies the following expression: d≧0.8D.  
     
     
         41 . A semiconductor device comprising: 
 (a) a first metal film formed above a semiconductor chip;    (b) a ball portion formed over said first metal film and made of a second metal; and    (c) an alloy layer of said first metal and said second metal which alloy layer has been formed between said first metal film and said ball portion,    (d) wherein the relationship between a diameter d of a contact region of said first metal film with said ball portion and a maximum peripheral diameter D of said ball portion satisfies the following expression: d≧0.8D.    
     
     
         42 . A semiconductor device comprising: 
 (a) a first metal film formed above a semiconductor chip;    (b) a ball portion formed over said first metal film and made of a second metal; and    (c) an alloy layer of said first metal and said second metal which alloy layer has been formed between said first metal film and said ball portion,    (d) wherein a contact region of said first metal film with said ball portion is at least 70% of a region defined by a maximum periphery of said ball portion.    
     
     
         43 . A manufacturing method of a semiconductor device, comprising the steps of: 
 (a) forming a first metal film above a semiconductor chip region;    (b) forming over said first metal film an insulating film having an opening at a pad portion over said first metal film; and    (c) adhering a ball portion made of a second metal onto said pad portion by means of ultrasonic thermo-compression bonding method at ultrasonic frequency of 110 kHz or greater.    
     
     
         44 . A manufacturing method of a semiconductor device according to  claim 43 , wherein said step (c) is conducted by increasing pressure applied to said pad portion while applying ultrasonic waves.  
     
     
         45 . A manufacturing method of a semiconductor device according to  claim 43 , further comprising the step of, after said step (c): 
 (d) covering and sealing said ball portion with a resin.    
     
     
         46 . A manufacturing method of a semiconductor device, comprising the steps of: 
 (a) forming a first metal film above a semiconductor chip region;    (b) forming over said first metal film an insulating film having an opening at a pad portion over said first metal film;    (c) adhering a ball portion made of a second metal onto said pad portion by means of ultrasonic thermo-compression bonding method at ultrasonic frequency of 110 kHz or greater;    (d) covering and sealing said ball portion with a resin; and    (e) after said step (d), preparing a plurality of sealed semiconductor chips similar to said sealed semiconductor chip obtained above, and exposing some of said plurality of sealed semiconductor chips to high temperature conditions to test the characteristics thereof.    
     
     
         47 . A manufacturing method of a semiconductor device, comprising the steps of: 
 (a) forming a first metal film above a semiconductor chip region;    (b) forming over said first metal film an insulating film having an opening at a pad portion over said first metal film;    (c) upon formation of a ball portion made of a second metal over said first metal film, forming an alloy layer of said first metal and said second metal in at least 70% of a contact region of said first metal film with said ball portion, thereby adhering said ball portion onto said pad portion;    (d) covering and sealing said ball portion with a resin; and    (e) after said step (d), preparing a plurality of sealed semiconductor chips similar to said semiconductor chip obtained above, and exposing some of said plurality of sealed semiconductor chips to high temperature conditions to test the characteristics of said semiconductor chips.    
     
     
         48 . A manufacturing method of a semiconductor device, comprising the steps of: 
 (a) forming a first metal film above a semiconductor chip region;    (b) forming over said first metal film an insulating film having an opening at a pad portion over said first metal film;    (c) upon formation of a ball portion made of a second metal over said first metal film, forming an alloy layer of said first metal and said second metal in at least 70% of a contact region of said first metal film with said ball portion, thereby adhering said ball portion onto said first metal film, and adjusting the shape of said ball portion so that a diameter d of said contact region and a maximum peripheral diameter D of said ball portion satisfy the following expression: d≧0.8D; and    (d) covering and sealing said ball portion with a resin.    
     
     
         49 . A manufacturing method of a semiconductor device, comprising the steps of: 
 (a) forming a first metal film above a semiconductor chip region;    (b) forming over said first metal film an insulating film having an opening at a pad portion over said first metal film;    (c) upon formation of a ball portion made of a second metal over said first metal film, forming an alloy layer of said first metal and said second metal in at least 70% of a contact region of said first metal film with said ball portion, thereby adhering said ball portion onto said first metal film, and adjusting the shape of said ball portion so that a diameter d of said contact region and a maximum peripheral diameter D satisfy the following expression: d≧0.8D;    (d) covering and sealing said ball portion with a resin; and    (e) after said step (d), preparing a plurality of sealed semiconductor chips similar to said sealed semiconductor chip obtained above, and exposing some of said plurality of sealed semiconductor chips to high temperature conditions to test the characteristics thereof.