Increased threshold uniformity of thermal ink transducers
US5639386A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 7, 1995 |
| Grant date | Jun 17, 1997 |
| Priority date | — |
| Expiry date | Mar 7, 2015 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB41J2/1646
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
The resistors of heater elements are formed by chemical vapor deposition of polycrystalline silicon at at least one of a flat temperature profile of 620.degree. C. and a ramped temperature profile of 620.degree. C. to 640.degree. C. in a first embodiment. Such method of forming the polysilicon result in a predominantly uniform grain size of approximately 1000 .ANG., where grain size can vary between 200 .ANG. to 1000 .ANG.. Alternatively, the resistors are formed by chemical vapor deposition of amorphous polysilicon at at least one of a flat temperature profile at a temperature below 580.degree. C. and a ramped temperature profile of 565.degree. C. to 575.degree. C. In the alternative embodiment, the polysilicon has a grain size of at least 1000 .ANG.. During the ion implantation of either p-type or n-type dopants into the polysilicon, a flood gun located in an ion implanter emits low energy electrons to neutralize the build-up of positive charges on the polysilicon surface. Because the low energy electrons prevent the build-up of electric charges on the surface of the polysilicon, the usual build-up of an electrical field on the surface of the polysilicon is eliminated, and the po…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.