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Manufacturing Semiconductor Bodies

IP.com Disclosure Number: IPCOM000090317D
Original Publication Date: 1969-Mar-01
Included in the Prior Art Database: 2005-Mar-05
Document File: 2 page(s) / 31K

Publishing Venue

IBM

Related People

Hellbardt, G: AUTHOR

Abstract

Some methods of manufacturing boron-doped silicon semiconductor bodies have a number of disadvantages. Thus, for example, in the case of the boron diffusion method using a reaction tube and an N(2), O(2), and BBr(3) gas mixture from which B(2)O(3) is generated, the extremely low vapor pressure produced even at higher diffusion temperatures is disadvantageous. Even under controlled conditions it is very difficult with this method to so adjust the O(2) and BBr(3) concentration that the low surface concentration in silicon necessary for the base diffusion of NPN transistors is obtained.

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Manufacturing Semiconductor Bodies

Some methods of manufacturing boron-doped silicon semiconductor bodies have a number of disadvantages. Thus, for example, in the case of the boron diffusion method using a reaction tube and an N(2), O(2), and BBr(3) gas mixture from which B(2)O(3) is generated, the extremely low vapor pressure produced even at higher diffusion temperatures is disadvantageous. Even under controlled conditions it is very difficult with this method to so adjust the O(2) and BBr(3) concentration that the low surface concentration in silicon necessary for the base diffusion of NPN transistors is obtained.

To overcome these difficulties, reaction tube RC is placed in front of diffusion tube DC which is heated to diffusion temperature and serves to produce B(2)O(3). The length of reaction tube RC is determined so that the reaction of BBr(3) or B(2)H(6) and O(2) to B(2)O(3) can be completed at a relatively high temperature. The gas issuing from tube RC is fed directly into tube DC in which semiconductor body W to be doped is covered with a boron silicate glass layer at a particular diffusion temperature T3, doping being effected from this layer.

Quartz wool M in exit zone CC ensures an accelerated precipitation of excessive B(2)O(3). The values T1 = 1000 degrees C, T2 = 900 degrees C, T3 = 1100 degrees C d = 50mm, and a = b = c = 15 cm are used in this method.

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