Browse Prior Art Database

Clean Loading P(2)O(5) Semiconductor Diffusion Technique

IP.com Disclosure Number: IPCOM000094225D
Original Publication Date: 1966-Jul-01
Included in the Prior Art Database: 2005-Mar-06
Document File: 2 page(s) / 58K

Publishing Venue

IBM

Related People

Benjamin, CE: AUTHOR [+2]

Abstract

In this system for semiconductor diffusion operations, P(2)O(5) converted to the orthorhombic form during bake-out at 360 degrees C for 35 minutes. The system utilizes a two-zone furnace with source zone 1 at 360 degrees C, and wafer diffusion zone II at 1050 degrees C. The time and temperatures can be varied as desired.

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Clean Loading P(2)O(5) Semiconductor Diffusion Technique

In this system for semiconductor diffusion operations, P(2)O(5) converted to the orthorhombic form during bake-out at 360 degrees C for 35 minutes. The system utilizes a two-zone furnace with source zone 1 at 360 degrees C, and wafer diffusion zone II at 1050 degrees C. The time and temperatures can be varied as desired.

Quartz furnace tube 1 in drawing A has a small-diameter round section in source zone I and a larger-sized square section 2 in the diffusion zone II. External projections, not shown, center the square section 2 in the furnace so that sleeve 3, for condensation, can be slid over its end. The other end has a ground taper joint to fit the source end cap 4. Close-fitting baffle 5 immediately behind source boat 6 prevents back-streaming of the P(2)O(5) laden gas and keeps that end of the quartzware completely clean.

Furnace tube 1 ends at a point in the furnace which is hotter than the condensation point of the P(2)O(5). During bake-out, sleeve 3, which overlaps tube 1 by about one inch, is inserted to catch all condensed P2O5. After bake- out, with reference to drawing B, the end section of tube 1 is replaced by a clean quartz piece.

This consists of adapter sleeve 8 being substituted for condenser sleeve 3. Loaded wafer boat 10 is inserted into the end cap. The nitrogen line is connected and now both this flow and the P(2)O(5) carrying flow exit at the exhaust hole before the end cap.

Wafers ar...