Rf sputtering of trigonal selenium films

Claim 1

A METHOD OF MAKING A PHOTOCONDUCTIVE IMAGING DEVICE WHICH COMPRISES: DIRECTLY DEPOSITING A THIN LAYER OF TRIGONAL SELENIUM ONTO A SUPPORTING CONDUCTIVE SUBSTRATE, SAID DEPOSITION COMPRISING RF SPUTTERING SAID FILM AT AN RF INPUT POWER OF UP TO ABOUT 1 TO 3 WATTS/CM2 WHILE MAINTAINING A CORRESPONDING ELEMENTAL SELENIUM FLUX DENSITY UP TO ABOUT 10**16 ATOMS /CM2/SEC. IN AN INERT ATMOSPHERE UNDER VACUUM CONDITIONS, SAID DEPOSITION BEING CARRIED OUT WHILE MAINTAINING THE CONDUCTIVE SUBSTRATE AT A TEMPERATURE IN THE RANGE OF ABOUT 70* TO 130*C, SAID SUBSTRATE BEING OF A MATERIAL WHICH IS ELECTRICALLY BLOCKING WITH RESPECT TO TRIGONAL SELENIUM OR IS COVERED WITH A THIN ELECTRICALLY BLOCKING LAYER TO PREVENT CHARGE INJECTION AND WHICH HAS AN ADEQUATE NUMBER OF HETEROGENEOUS NUCLEATION CENTERS FOR TRIGONAL SELENIUM GROWTH BUT NO SO MANY SITES SO THAT THE PROCESS GIVES RISE TO A FORM OF TRIGONAL SELENIUM WHICH IS TOO CONDUCTIVE IN THE DARK TO BE OF XEROGRAPHIC UTILITY AND SUCH MATERIAL HAVING A SUFFICIENTLY HIGH SUBSTRATEVAPOR TENSION AND A SUFFICIENTLY LOW SUBSTRATE-SELENIUM INTERFACIAL TENSION TO PERMIT THE EFFECTIVE APPLICATION OF THE TRIGONAL SELENIUM TO ITS SURFACE BY RF SPUTTERING.

Claim 2

A METHOD OF MAKING A PHOTOCONDUCTIVE IMAGING DEVICE WHICH COMPRISES: DIRECTLY DEPOSITING A THIN LAYER OF TRIGONAL SELENIUM ONTO A SUPPORTING CONDUCTIVE SUBSTRATE, SAID DEPOSITION COMPRISING RF SPUTTERING SAID FILM AT AN RF INPUT POWER OF UP TO ABOUT 1 TO 3 WATTS/CM2 WHILE MAINTAINING A CORRESPONDING ELEMENTAL SELENIUM FLUX DENSITY UP TO ABOUT 10**16 ATOMS /CM2/SEC. IN AN INERT ATMOSPHERE UNDER VACUUM CONDITIONS, SAID DEPOSITION BEING CARRIED OUT WHILE MAINTAINING THE CONDUCTIVE SUBSTRATE AT A TEMPERATURE IN THE RANGE OF ABOUT 70* TO 130*C, SAID SUBSTRATE BEING OF A MATERIAL WHICH IS ELECTRICALLY BLOCKING WITH RESPECT TO TRIGONAL SELENIUM OR IS COVERED WITH A THIN ELECTRICALLY BLOCKING LAYER TO PREVENT CHARGE INJECTION AND WHICH HAS AN ADEQUATE NUMBER OF HETEROGENEOUS NUCLEATION CENTERS FOR TRIGONAL SELENIUM GROWTH BUT NO SO MANY SITES SO THAT THE PROCESS GIVES RISE TO A FORM OF TRIGONAL SELENIUM WHICH IS TOO CONDUCTIVE IN THE DARK TO BE OF XEROGRAPHIC UTILITY AND SUCH MATERIAL HAVING A SUFFICIENTLY HIGH SUBSTRATEVAPOR TENSION AND A SUFFICIENTLY LOW SUBSTRATE-SELENIUM INTERFACIAL TENSION TO PERMIT THE EFFECTIVE APPLICATION OF THE TRIGONAL SELENIUM TO ITS SURFACE BY RF SPUTTERING.