Temperature controlled substrate for VLSI construction having minimal parasitic feedback
US5798502A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 10, 1996 |
| Grant date | Aug 25, 1998 |
| Priority date | — |
| Expiry date | May 10, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG05D23/1913
- WIPO fieldControl
- WIPO sectorInstruments
Abstract
A closed loop control system for controlling the temperature of a heated substrate is presented. In the preferred embodiment, the closed loop control system is implemented substantially or completely on a single substrate. The closed loop control system comprises means to reduce or eliminate parasitic feedback in the control system. In one aspect of the present invention, the mechanism for reducing the effects of parasitic feedback comprises a mechanism to prevent minority carriers from collecting around the base of the temperature sensing device. The mechanism for preventing minority carriers from collecting around the base of the temperature sensing device can be one or more guard rings which attract the minority carriers and prevent them from collecting around the base of the temperature sensor. In another aspect of the present invention, the mechanism for reducing the effects of parasitic feedback can be a sample and hold circuit which approximates the theoretically ideal sample and hold circuit in order to present a substantially open circuit to the parasitic feedback.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.