公开(公告)号：US3901745A

公开(公告)日：1975-08-26

申请号：US43813974

申请日：1974-01-30

Applicant: INT STANDARD ELECTRIC CORP

Inventor： PION MARTIN

IPC: H01J1/34 ,  H01J9/12 ,  H01L7/38

CPC classification number: H01J1/34 ,  H01J9/12 ,  H01J2201/3423 ,  Y10S148/051 ,  Y10S148/056 ,  Y10S148/072 ,  Y10S148/12 ,  Y10S148/135

Abstract: A gallium arsenide photocathode is formed from a substrate of gallium arsenide on which are grown a first thin gallium aluminum arsenide layer and a further thin active layer of gallium arsenide. A coating of wax is applied over the thin active GaAs layer and around the sides and peripheral edges of the structure. A central region of the GaAs substrate is then etched to expose the inner GaAlAs layer while leaving a supporting rim around the edges. The rim permits use of a thinner GaAlAs layer.

公开(公告)号：US3901744A

公开(公告)日：1975-08-26

申请号：US43630074

申请日：1974-01-24

Applicant: INT STANDARD ELECTRIC CORP

Inventor： BOLGER DEREK E ,  PION MARTIN

IPC: H01J9/12 ,  H01L21/00 ,  H01L21/208 ,  H01L21/306 ,  H01L7/38

CPC classification number: H01L21/30612 ,  H01J9/12 ,  H01L21/00 ,  H01L21/02395 ,  H01L21/02463 ,  H01L21/02546 ,  H01L21/02625 ,  H01L21/02639 ,  Y10S438/928 ,  Y10S438/977

Abstract: A method of making a semiconductor device avoids the problems of excessive liquid phase epitaxial growth at the edges of a slice which can interfere with processing in a sliding boat technique. A layer of refractory masking material is deposited on the front and back surfaces of the substrate slice. The central area of the front surface is then etched to leave the protective layer on the sides, edges and back. This prevents the undesired growth at the sides during the subsequent steps of growing semiconductor layers on the substrate. The slice is placed in a recess in a graphite boat having a sliding portion containing melts which contact the slice to grow first and second semiconductor layers. The central area of the back masking layer and substrate are then etched away to expose the first layer.