Browse Prior Art Database

Dual Vacuum System for 2x Sio2 Sputtering Machines

IP.com Disclosure Number: IPCOM000061101D
Original Publication Date: 1986-Jun-01
Included in the Prior Art Database: 2005-Mar-09
Document File: 2 page(s) / 38K

Publishing Venue

IBM

Related People

Collins, JF: AUTHOR [+3]

Abstract

This invention provides a new design which improves speed and efficiency of SiO2 sputtering machines used in semiconductor manufacturing processes. The SiO2 deposition chambers require conditioning and burn- in after a tooling change and before deposition of insulation on product. Previously, diffusion pumps were used during burn-in, and contamination resulted. The proposal suggests use of a mechanical pump and roots blower combination for burn-in and a cryopump and LN2 (liquid nitrogen) Meissner for pumping during deposition. The new design, which departs from traditional vacuum pumping systems, is shown in the figure. Peak efficiencies can be obtained in each of the three pressure ranges of interest: B = 760 mm to 1 Torr; C = 1 to 8 x 10-5 Torr; D = 8 x 10-5 to 5 x 10-8 Torr.

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 70% of the total text.

Page 1 of 2

Dual Vacuum System for 2x Sio2 Sputtering Machines

This invention provides a new design which improves speed and efficiency of SiO2 sputtering machines used in semiconductor manufacturing processes. The SiO2 deposition chambers require conditioning and burn- in after a tooling change and before deposition of insulation on product. Previously, diffusion pumps were used during burn-in, and contamination resulted. The proposal suggests use of a mechanical pump and roots blower combination for burn-in and a cryopump and LN2 (liquid nitrogen) Meissner for pumping during deposition. The new design, which departs from traditional vacuum pumping systems, is shown in the figure. Peak efficiencies can be obtained in each of the three pressure ranges of interest: B = 760 mm to 1 Torr; C = 1 to 8 x 10-5 Torr; D = 8 x 10-5 to 5 x 10-8 Torr. A 2 x 10-6 Torr ion-gauge background pressure range can be obtained in 12 minutes, sequencing the pumping elements as follows: 1. Mechanical pumping to 1 Torr (26 cfm) 2. LN2 trap pumping (1000 l/s)
3. Roots blower pumping to 8 x 10-5 Torr (76 average cfm) 4. LN2 Meissner pumping (15,000 l/s) 5. Cryogenic pumping (9000 l/s water) During sputter deposition, roots blower pumping (line C) will support 25% of trace element reactive gases flashed with 75% noble gas up to 100 sccm throughput. The oil filter 7 will remove and accumulate up to 1000 ml of acid content of the reactive gases without the need of any special system preparation requirem...