Bubble memory optimization by adjusting properties of quartz film
AssigneeSperry Corporation
InventorsMartin J. Casey, Barry F. Stein, Herman E. Wetterskog
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Abstract
A bubble memory device and method of fabrication are disclosed which establish that there is a correlation between bubble memory performance and the properties of a quartz film, which is interposed between the bubble film and metallic overlays, namely, the permalloy and/or conductor layers of the device. Specifically, it has been established that there is a correlation between improved device performance and a low p-etch rate which is a measurement that establishes certain elastic constants of the quartz (i.e., the response of the device to stress).
Claims4
A bubble memory device comprising a substrate, a magnetic bubble film formed on said substrate, a conductor and a permalloy film the improvement comprising,
- a. a quartz layer interposed between said conductor and said bubble film, and between said conductor and said permalloy film, said quartz layer having a stiffness characteristic obtained by a p-etch deposition rate below 6 A/second.
A bubble memory device comprising:
- a. a substrate;
- b. a magnetic bubble film positioned on said substrate;
- c. a first quartz layer positioned on said bubble film;
- d. a metal conductor positioned on said quartz layer;
- e. a second quartz layer positioned over said metal conductor, said first and second quartz layers having been deposited with a p-etch rate below 6 A/second;
- f. a permalloy circuit positioned upon said second quartz layer, said permalloy circuit and said metal conductor being utilized to propagation bubbles around said circuit.
Dependencies are inferred from the claim text.