Here's the entire Transporter Process:
Stage 1 & 2:
Stage 3 & 4:
There's 2x Parts to the Transporter System:
+ The Matter Stream
The 'Phase Transition Coils' begins to disassemble you on a atomic level by partially unbinding the atomic energy at a Sub-Atomic level.
NOTE: There are LIMITS to this process since the Matter Stream can be held in the Pattern Buffer (Which sits right below the Transporter Pad and is about the size of an entire deck) for 420 seconds (7 minutes) before degradation occurs. That's a the NORMAL limit.
+ The Data Stream:
The 'Molecular Imaging Scanner' makes a detailed scan of every atom in your body and each atoms individual Quantum State
This "Data Portion" can be retained forever and StarFleet has a policy of retaining the last few images of your body at a Atomic Level along with it's Quantum State.
Final Analysis on extending your time in the Patter Buffer in the Transporter:
The pattern buffer is a key component of the transporter system. The buffer is used to temporarily store the matter stream, following dematerialization, but prior to sending the stream to its target whilst the other systems function. This is done because of the relative motion of transporter and target. By temporarily storing the matter stream, the Doppler compensators have the time to adjust the targeting scanners.
A matter stream cannot be stored indefinitely in the buffer; after 420 seconds (7 minutes), the stored pattern will degrade and the object will be lost. The only known record of a person surviving in a buffer longer than the expected figure was Captain Montgomery Scott on board the USS Jenolan, NCC-2010. Following the Jenolan's crash-landing on a Dyson sphere, Scott, with the help of Matt Franklin, was able to store his pattern in the buffer for 75 years. This was achieved by disabling the rematerialization subroutine, connecting the phase inducers to the emitter array, bypassing the override, and locking the buffer into a continuous diagnostic cycle. Although Captain Scott's pattern suffered less than 0.003% degradation, and was successfully recovered by Geordi La Forge of the USS Enterprise-D in 2369, Franklin was irretrievable, as one of the inducers had failed, causing a 53% degradation in his pattern.
Starships can also transfer patterns from one pattern buffer to another by "locking on" to the target buffer and energizing.
To eliminate the medical condition called transporter psychosis, Federation transporters are equipped with multiplex pattern buffers.
What Scotty did was a desperate MacGuyver like "Jerry Rig" of the normal Transporter System.
Scotty himself suffered some degradation at 0.003% of his Molecular structure, survivable & he got lucky by the stroke of the writers pen & Plot Armor.
His buddy Franklin lost 53% of the pattern for whatever reason and he died.
If you intend on pursuing this route of storage, you need to make sure that whatever routine is used to keep the Matter Stream alive and not degrading over time past 7 minutes gets researched and tested thoroughly before putting into practical use.
A 50% survival rate over 75 years isn't good IMO, and who knows what other technical failures could occur.
If your computer hardware dies, power outage to any system, any of the components die due to natural degradation over time or other outside factors.
Storing people in the Pattern Buffer is very risky and not recommended in general.