Browse Prior Art Database

Liquid Phase Epitaxy Wafer Holder

IP.com Disclosure Number: IPCOM000085325D
Original Publication Date: 1976-Mar-01
Included in the Prior Art Database: 2005-Mar-02
Document File: 2 page(s) / 29K

Publishing Venue

IBM

Related People

Frei, H: AUTHOR [+2]

Abstract

The liquid phase epitaxy (LPE) of garnet films on garnet substrates from a supercooled liquid using a conventional prior art LPE wafer holder, as shown in Fig. 1, produces uniform thin film over most of the wafer's bottom surface. The edge of the wafer, however, generally collects droplets of PbO melt which produce small round growths of garnet at the wafer's edge. The growths have the appearance of flat mesas. These mesas interfere with subsequent photolithographic operations.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 86% of the total text.

Page 1 of 2

Liquid Phase Epitaxy Wafer Holder

The liquid phase epitaxy (LPE) of garnet films on garnet substrates from a supercooled liquid using a conventional prior art LPE wafer holder, as shown in Fig. 1, produces uniform thin film over most of the wafer's bottom surface. The edge of the wafer, however, generally collects droplets of PbO melt which produce small round growths of garnet at the wafer's edge. The growths have the appearance of flat mesas. These mesas interfere with subsequent photolithographic operations.

The top surface of the wafer is similar to the bottom surface except for the 4 pi M(s) value. The top surface consistently shows a value of 4 pi M(s) that is about 40% lower than the bottom. The growing of two films in a back-to-back configuration is not possible as long as the reverse film properties differ from the front.

The LPE wafer holder shown in Fig. 2 yields films with fewer mesas and more similar reverse film properties. In this design, the wafer supports are aligned in the plane of the wafer extending out from the wafer by about 3/8''. The ends of support are machined with a notch for securing the wafer. The wafer holder (Fig. 2) is supported by horizontal legs or supports, whereas the prior art wafer holder (Fig. 1) is supported by vertical legs.

The new design holder has three distinct advantages over the original:

1) Mesa formation at the wafer edge is greatly reduced.

2) The removal of the wafer from the holder at the end

of a run does not r...